Background: Salivary gland tumours (SGTs) are rare, but recent reports suggest an increasing incidence. Although there are previous Nigerian studies on the patterns of SGTs, patterns and trends of disease may change o...Background: Salivary gland tumours (SGTs) are rare, but recent reports suggest an increasing incidence. Although there are previous Nigerian studies on the patterns of SGTs, patterns and trends of disease may change over time. The aim of this study was to describe the pattern of presentation of SGTs, and to determine the trends in occurrence of SGTs at Federal Teaching Hospital (FTH), Gombe over a period of 15 years. Method: This descriptive study included cases of histologically diagnosed SGTs from January 2008 to December 2022. Relevant information (age, gender, site, year of diagnosis, and histopathologic diagnosis) was extracted from the cancer registers and histopathologic records. The lesions were then categorized into benign and malignant SGTs and grouped into three groups spanning 5 years each based on the year of diagnosis. Data analysis was done using IBM SPSS version 23, and p ≤ 0.05 was considered statistically significant. Results: There were 93 (61.2%) benign and 59 (38.8%) malignant SGTs. Benign SGTs had a mean age of 36.4 ± 13.6 years, and were more common in females (57.0%), and in the parotid (41.9%). Pleomorphic adenoma (94.6%) was the most common benign SGT. Malignant SGTs had a mean age of 44.5 ± 18.4 years, with male predilection (54.2%) and occurrence mostly in the palate (27.6%) and parotid (22.4%). Mucoepidermoid carcinoma (39.0%) and adenoid cystic carcinoma (32.2%) were the most frequent malignant SGTs. The mean age of occurrence of malignant SGTs was significantly higher than that of benign SGTs (p = 0.005). The trend analysis showed that there has been a steady rise in the proportion of males presenting with malignant SGTs. Similarly, there has been a steady increase in the frequency of benign SGTs in the parotid. The palate was the predominant site for the malignant SGTs between 2008 and 2012, but in the last five years (2018 to 2022), the parotid has become the predominant site. Over the duration of the study, the ratio of benign to malignant SGTs has remained relatively constant. Conclusion: While the overall pattern of presentation of SGTs in Gombe is similar to reports in the literature, this study has identified some changes in trends over the years.展开更多
Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological rese...Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological research, especially in those of complex secondary forest regions with confusing mosaics of land cover. Trend surface analysis which used in community and population ecological researches was introduced to reveal the landscape pattern. A reasonable and reliable approach for application of trend surface analysis was provided in detail. As key steps of the approach, uniform grid point sampling method was developed. The efforts were also concentrated at an example of Guandishan forested landscape. Some basic rules of spatial distribution of landscape elements were exclaimed. These will be benefit to the further study in the area to enhance the forest sustainable management and landscape planning.展开更多
In this paper, first, based on landscape ecology theories, we respectively selected indexes from 4 aspects, area, edge, shape, and density, of the landscape type to describe the status of forest landscape patterns, an...In this paper, first, based on landscape ecology theories, we respectively selected indexes from 4 aspects, area, edge, shape, and density, of the landscape type to describe the status of forest landscape patterns, and we established the stability index of landscape pattern (LSBI). Then, based on geo-statistical theories, we divided the forest in the reservoir area into 3990 grids of 4 km × 4 km using network technology and employing ordinary Kriging modelling to make trend surface analyses of the forest resources in the reservoir area. Finally, based on statistics principles, we used sampling theory to systematically extract 227 samples to obtain 7 periods of remote-sensing data from 1990a to 2012a. Then, we classified and extracted the forest in the sampling area using remote sensing, and we analysed each result with an Autoregressive Integrated Moving Average Model (ARIMA) time-series model. The results indicated the following: 1) the landscape structure of the reservoir area was primarily needle-leaved forest, broad-leaved forest and bush forest, and the mixed stands and bamboo stands were secondary;2) the difference of the forest landscape pattern stability in the reservoir area, in all directions, was not significant, but the southern region was slightly more stable;and 3) the stability of the forest landscape pattern in the reservoir area increased from 1990a to 2012a. It kept increasing until 2016a. This study provides a theoretical basis for the reasonable management and decisions about the forest resources in the Three Gorges Reservoir Area. Meanwhile, it also explores methods for relevant research and has practical significance.展开更多
叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反...叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反演了乌鲁木齐市夏季LAI时间序列数据。引入景观指数分析乌鲁木齐市2016~2022年不同等级绿色空间的组分与结构变化特征;使用结合Sen斜率估计的M-K趋势检验分析了乌鲁木齐市夏季LAI的变化趋势;并通过地理探测器分析了不同驱动因子对LAI的驱动作用。结果表明:(1)建成区内部多为低密度植被区域覆盖,高密度植被覆盖区域集中于城市边缘;(2)乌鲁木齐市的绿色空间面积主要呈减少趋势。(3)影响乌鲁木齐市绿色空间的驱动因子主要为土地利用类型和降水量;(4)交互探测表明驱动因子交互作用影响力强于单个驱动因子。展开更多
The identification of control chart patterns is very important in statistical process control. Control chart patterns are categorized as natural and unnatural. The presence of unnatural patterns means that a process i...The identification of control chart patterns is very important in statistical process control. Control chart patterns are categorized as natural and unnatural. The presence of unnatural patterns means that a process is out of statistical control and there are assignable causes for process variation that should be investigated. This paper proposes an artificial neural network algorithm to identify the three basic control chart patterns;natural, shift, and trend. This identification is in addition to the traditional statistical detection of runs in data, since runs are one of the out of control situations. It is assumed that a process starts as a natural pattern and then may undergo only one out of control pattern at a time. The performance of the proposed algorithm was evaluated by measuring the probability of success in identifying the three basic patterns accurately, and comparing these results with previous research work. The comparison showed that the proposed algorithm realized better identification than others.展开更多
Shigellosis causes diarrheal disease in humans in both developed and developing countries, and multi-drug resistance in Shigella is an emerging problem. Understanding changing resistance patterns is important in deter...Shigellosis causes diarrheal disease in humans in both developed and developing countries, and multi-drug resistance in Shigella is an emerging problem. Understanding changing resistance patterns is important in determining appropriate antibiotic treatments. This meta-analysis systematically evaluated aminoglycoside resistance in Shigella. A systematic review was constructed based on MEDLINE and EMBASE databases. Randomeffect models or fixed-effect models were used based on P value considering the possibility of heterogeneity between studies for meta-analysis. Data manipulation and statistical analyses were performed using software STATA 11.0. By means of meta-analysis, we found a lower resistance to three kinds of aminoglycosides in the Europe-America areas during the 12 year study period than that of the Asia-Africa areas. Kanamycin resistance was observed to be the most common drug resistance among Shigella isolates with a prevalence of 6.88% （95%CI： 6.36%-7.43%）. Comparison of data from Europe-America and Asia-Africa areas revealed that Shigella flexneri resistance was greater than the resistance calculated for Shigella sonnei. Importantly, Shigella sonnei has played a significant role in aminoglycoside-resistance in recent years. Similarly, data showed that resistance to these drugs in children was higher than the corresponding data of adults. In conclusion, aminoglycoside-resistant Shigella is not an unusual phenomenon worldwide. Distribution in Shigella resistance differs sharply based on geographic areas, periods of time and subtypes. The results from the present study highlight the need for con- tinuous surveillance of resistance and control of antibiotic usage.展开更多
文摘Background: Salivary gland tumours (SGTs) are rare, but recent reports suggest an increasing incidence. Although there are previous Nigerian studies on the patterns of SGTs, patterns and trends of disease may change over time. The aim of this study was to describe the pattern of presentation of SGTs, and to determine the trends in occurrence of SGTs at Federal Teaching Hospital (FTH), Gombe over a period of 15 years. Method: This descriptive study included cases of histologically diagnosed SGTs from January 2008 to December 2022. Relevant information (age, gender, site, year of diagnosis, and histopathologic diagnosis) was extracted from the cancer registers and histopathologic records. The lesions were then categorized into benign and malignant SGTs and grouped into three groups spanning 5 years each based on the year of diagnosis. Data analysis was done using IBM SPSS version 23, and p ≤ 0.05 was considered statistically significant. Results: There were 93 (61.2%) benign and 59 (38.8%) malignant SGTs. Benign SGTs had a mean age of 36.4 ± 13.6 years, and were more common in females (57.0%), and in the parotid (41.9%). Pleomorphic adenoma (94.6%) was the most common benign SGT. Malignant SGTs had a mean age of 44.5 ± 18.4 years, with male predilection (54.2%) and occurrence mostly in the palate (27.6%) and parotid (22.4%). Mucoepidermoid carcinoma (39.0%) and adenoid cystic carcinoma (32.2%) were the most frequent malignant SGTs. The mean age of occurrence of malignant SGTs was significantly higher than that of benign SGTs (p = 0.005). The trend analysis showed that there has been a steady rise in the proportion of males presenting with malignant SGTs. Similarly, there has been a steady increase in the frequency of benign SGTs in the parotid. The palate was the predominant site for the malignant SGTs between 2008 and 2012, but in the last five years (2018 to 2022), the parotid has become the predominant site. Over the duration of the study, the ratio of benign to malignant SGTs has remained relatively constant. Conclusion: While the overall pattern of presentation of SGTs in Gombe is similar to reports in the literature, this study has identified some changes in trends over the years.
文摘Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological research, especially in those of complex secondary forest regions with confusing mosaics of land cover. Trend surface analysis which used in community and population ecological researches was introduced to reveal the landscape pattern. A reasonable and reliable approach for application of trend surface analysis was provided in detail. As key steps of the approach, uniform grid point sampling method was developed. The efforts were also concentrated at an example of Guandishan forested landscape. Some basic rules of spatial distribution of landscape elements were exclaimed. These will be benefit to the further study in the area to enhance the forest sustainable management and landscape planning.
文摘In this paper, first, based on landscape ecology theories, we respectively selected indexes from 4 aspects, area, edge, shape, and density, of the landscape type to describe the status of forest landscape patterns, and we established the stability index of landscape pattern (LSBI). Then, based on geo-statistical theories, we divided the forest in the reservoir area into 3990 grids of 4 km × 4 km using network technology and employing ordinary Kriging modelling to make trend surface analyses of the forest resources in the reservoir area. Finally, based on statistics principles, we used sampling theory to systematically extract 227 samples to obtain 7 periods of remote-sensing data from 1990a to 2012a. Then, we classified and extracted the forest in the sampling area using remote sensing, and we analysed each result with an Autoregressive Integrated Moving Average Model (ARIMA) time-series model. The results indicated the following: 1) the landscape structure of the reservoir area was primarily needle-leaved forest, broad-leaved forest and bush forest, and the mixed stands and bamboo stands were secondary;2) the difference of the forest landscape pattern stability in the reservoir area, in all directions, was not significant, but the southern region was slightly more stable;and 3) the stability of the forest landscape pattern in the reservoir area increased from 1990a to 2012a. It kept increasing until 2016a. This study provides a theoretical basis for the reasonable management and decisions about the forest resources in the Three Gorges Reservoir Area. Meanwhile, it also explores methods for relevant research and has practical significance.
文摘叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反演了乌鲁木齐市夏季LAI时间序列数据。引入景观指数分析乌鲁木齐市2016~2022年不同等级绿色空间的组分与结构变化特征;使用结合Sen斜率估计的M-K趋势检验分析了乌鲁木齐市夏季LAI的变化趋势;并通过地理探测器分析了不同驱动因子对LAI的驱动作用。结果表明:(1)建成区内部多为低密度植被区域覆盖,高密度植被覆盖区域集中于城市边缘;(2)乌鲁木齐市的绿色空间面积主要呈减少趋势。(3)影响乌鲁木齐市绿色空间的驱动因子主要为土地利用类型和降水量;(4)交互探测表明驱动因子交互作用影响力强于单个驱动因子。
文摘The identification of control chart patterns is very important in statistical process control. Control chart patterns are categorized as natural and unnatural. The presence of unnatural patterns means that a process is out of statistical control and there are assignable causes for process variation that should be investigated. This paper proposes an artificial neural network algorithm to identify the three basic control chart patterns;natural, shift, and trend. This identification is in addition to the traditional statistical detection of runs in data, since runs are one of the out of control situations. It is assumed that a process starts as a natural pattern and then may undergo only one out of control pattern at a time. The performance of the proposed algorithm was evaluated by measuring the probability of success in identifying the three basic patterns accurately, and comparing these results with previous research work. The comparison showed that the proposed algorithm realized better identification than others.
基金funded by National Natural Science Foundation of China (No. 81000754)a grant from the Key Laboratory for Laboratory Medicine of Jiangsu Province of China (No. XK201114)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Shigellosis causes diarrheal disease in humans in both developed and developing countries, and multi-drug resistance in Shigella is an emerging problem. Understanding changing resistance patterns is important in determining appropriate antibiotic treatments. This meta-analysis systematically evaluated aminoglycoside resistance in Shigella. A systematic review was constructed based on MEDLINE and EMBASE databases. Randomeffect models or fixed-effect models were used based on P value considering the possibility of heterogeneity between studies for meta-analysis. Data manipulation and statistical analyses were performed using software STATA 11.0. By means of meta-analysis, we found a lower resistance to three kinds of aminoglycosides in the Europe-America areas during the 12 year study period than that of the Asia-Africa areas. Kanamycin resistance was observed to be the most common drug resistance among Shigella isolates with a prevalence of 6.88% （95%CI： 6.36%-7.43%）. Comparison of data from Europe-America and Asia-Africa areas revealed that Shigella flexneri resistance was greater than the resistance calculated for Shigella sonnei. Importantly, Shigella sonnei has played a significant role in aminoglycoside-resistance in recent years. Similarly, data showed that resistance to these drugs in children was higher than the corresponding data of adults. In conclusion, aminoglycoside-resistant Shigella is not an unusual phenomenon worldwide. Distribution in Shigella resistance differs sharply based on geographic areas, periods of time and subtypes. The results from the present study highlight the need for con- tinuous surveillance of resistance and control of antibiotic usage.
