I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessa...I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessary is the response variable, and elevation, slope steepness, maximum snow depth, annual precipitation, geology, soil, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geology, soil, slope aspect, and vegetation type are categorical data. A Poisson distribution is assumed for the response variable, with a log-link function. Elevation, slope steepness, maximum snow depth, annual precipitation, site index, and vegetation type had a significant effect on weeding duration. Among the eight models with the smallest Akaike information criterion （AIC）, I chose the model with no multicollinearity among the explanatory variables. The weeding-duration model includes site index, maximum snow depth, slope steepness （angle） and vegetation type as explanatory variables; elevation and annual precipitation were not included in the selected model because of multicollinearity with maximum snow depth. This model is useful for cost-benefit analyses of afforestation or reforestation with Abies sachalinensis.展开更多
Background: Peripheral artery disease (PAD) is the least recognized form of atherosclerosis and may even result in amputation if the diagnosis is delayed. Manual pulse palpation is the traditional way to diagnose PAD....Background: Peripheral artery disease (PAD) is the least recognized form of atherosclerosis and may even result in amputation if the diagnosis is delayed. Manual pulse palpation is the traditional way to diagnose PAD. Doppler ultrasonographic measurement of ankle-brachial index (ABI) is the gold standard diagnosing method but requires training and is not necessarily available as an outpatient procedure. Using automated oscillometric blood pressure devices has been suggested as an easier method for measuring the ABI. Methods: A single observer palpated the arterial dorsalis pedis, examined hand joints and measured the ABI of one hundred diabetic patients using both Doppler and oscillometric methods. The purpose of this study was to compare the oscillometric method and the manual diagnosing methods to the gold standard method of using a hand held Doppler device for measuring the ABI and detecting PAD. Results: ABI was abnormal in 24 patients (24%) (22 males, 2 females) when measured with the Doppler method. Of these 24 patients, the oscillometric method would have missed 12 giving 12 false negatives. We found that the sensitivity of the oscillometric method was 50.0% and specificity 90.8%. Clinical examination with palpation of ADP combined with limited joint mobility (LJM) scoring would have missed only four cases. Conclusions: Although the oscillometric method is easy and accessible, it is not sensitive enough to be used as the only method in measuring ABI. The simple and inexpensive ADP pulse palpation combined with testing for LMJ was able to find 20 of the 24 (83%) patients with an abnormal ABI measured by Doppler stethoscope.展开更多
BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (...BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (CI) is rare. OBJECTIVE: To investigate the possible risk factor of cerebral infarction plus peripheral arterial disease (PAD), compare metabolic characteristics of patients who having CI plus PAD or only having CI, and understand the significance of ABI on screening and diagnosing CI plus PAD of lower limb. DESIGN: Contrast observation based on CI patients. SETTING: Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region. PARTICIPANTS: A total of 124 CI patients were selected from Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region from July 2005 to April 2006, including 72 males and 52 females aged from 45 to 88 years. All patients met the diagnostic criteria of cerebrovascular disease established by National Academic Conference of Cerebrovascular Diseases in 1995 and determined as cerebral infarction with MRI or CT examination. All patients provided informed consent. There were 46 cases (37.2%) with CI plus PAD and 78 cases (62.8%) only with CI. METHODS: Blood pressure of bilateral ankles and upper extremities was measured at plain clinostatism with DINAMAP blood pressure monitor (GE Company). The ratio between average systolic pressure of lateral ankle and average systolic pressure of both upper extremities was regarded as ABI. The normal ABI was equal to or more than 0.9. If ABI < 0.9 occurred at one side, patients were diagnosed as PAD. On the second morning after hospitalization, blood was collected to measure fasting blood glucose (FBG), 2-hour postprandial blood glucose (PBG2h), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Among them, blood glucose, lipid and other biochemical markers were measured with enzyme chemistry assay and HbA1c was measured with HbA1c meter based on high liquid phase. Measurement data and enumeration data were compared with t test and Chi-square test, and multiple factors were dealt with Logistic regression analysis and multivariate linear regression analysis. MAIN OUTCOME MEASURES: Results of correlation between ABI and metabolic markers with multivariate linear regression analysis; risk factors of CI plus PAD with Logistic regression analysis; comparisons of metabolic markers between PAD and non-PAD patients. RESULTS: All 124 patients with acute CI were involved in the final analysis. ① Comparisons of metabolic markers: Levels of serum LDL-C and uric acid (UA) were higher of PAD patients than those of non-PAD patients (t =2.051 9, 3.339 1, P < 0.05); however, there were no significant differences among other metabolic markers (P > 0.05). ② Results of multivariate linear regression analysis: PBG2h, LDL-C and UA were obvious correlation with ABI of posterior tibial artery of lower limb and dorsal pedis artery (partial regression coefficient = -0.231 to -1.010, P < 0.05). ③ Risk factors of CI plus PAD with Logistic regression analysis: Age, smoking history, sum of CI focus (≥3) and LDL-C were independent risk factor of CI plus PAD (OR =1.524-5.422, P < 0.05-0.01). CONCLUSION: ① Levels of serum LDL-C and UA of patients with CI plus PAD are high. ② ABI of lower limbs is correlation with PBG2h, LDL-C and UA. In addition, measuring ABI is beneficial for early diagnosing PAD of lower limbs of patients who have poorly controlled blood glucose, abnormal lipid and poor renal function. ③ Age, LDL-C and sum of CI focus (≥3) are independent risk factors of CI plus PAD. It is of significance for screening non-PAD patients to evaluate risk degrees and prognosis and select therapeutic methods based on ABI measurement.展开更多
文摘I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessary is the response variable, and elevation, slope steepness, maximum snow depth, annual precipitation, geology, soil, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geology, soil, slope aspect, and vegetation type are categorical data. A Poisson distribution is assumed for the response variable, with a log-link function. Elevation, slope steepness, maximum snow depth, annual precipitation, site index, and vegetation type had a significant effect on weeding duration. Among the eight models with the smallest Akaike information criterion （AIC）, I chose the model with no multicollinearity among the explanatory variables. The weeding-duration model includes site index, maximum snow depth, slope steepness （angle） and vegetation type as explanatory variables; elevation and annual precipitation were not included in the selected model because of multicollinearity with maximum snow depth. This model is useful for cost-benefit analyses of afforestation or reforestation with Abies sachalinensis.
文摘Background: Peripheral artery disease (PAD) is the least recognized form of atherosclerosis and may even result in amputation if the diagnosis is delayed. Manual pulse palpation is the traditional way to diagnose PAD. Doppler ultrasonographic measurement of ankle-brachial index (ABI) is the gold standard diagnosing method but requires training and is not necessarily available as an outpatient procedure. Using automated oscillometric blood pressure devices has been suggested as an easier method for measuring the ABI. Methods: A single observer palpated the arterial dorsalis pedis, examined hand joints and measured the ABI of one hundred diabetic patients using both Doppler and oscillometric methods. The purpose of this study was to compare the oscillometric method and the manual diagnosing methods to the gold standard method of using a hand held Doppler device for measuring the ABI and detecting PAD. Results: ABI was abnormal in 24 patients (24%) (22 males, 2 females) when measured with the Doppler method. Of these 24 patients, the oscillometric method would have missed 12 giving 12 false negatives. We found that the sensitivity of the oscillometric method was 50.0% and specificity 90.8%. Clinical examination with palpation of ADP combined with limited joint mobility (LJM) scoring would have missed only four cases. Conclusions: Although the oscillometric method is easy and accessible, it is not sensitive enough to be used as the only method in measuring ABI. The simple and inexpensive ADP pulse palpation combined with testing for LMJ was able to find 20 of the 24 (83%) patients with an abnormal ABI measured by Doppler stethoscope.
文摘BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (CI) is rare. OBJECTIVE: To investigate the possible risk factor of cerebral infarction plus peripheral arterial disease (PAD), compare metabolic characteristics of patients who having CI plus PAD or only having CI, and understand the significance of ABI on screening and diagnosing CI plus PAD of lower limb. DESIGN: Contrast observation based on CI patients. SETTING: Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region. PARTICIPANTS: A total of 124 CI patients were selected from Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region from July 2005 to April 2006, including 72 males and 52 females aged from 45 to 88 years. All patients met the diagnostic criteria of cerebrovascular disease established by National Academic Conference of Cerebrovascular Diseases in 1995 and determined as cerebral infarction with MRI or CT examination. All patients provided informed consent. There were 46 cases (37.2%) with CI plus PAD and 78 cases (62.8%) only with CI. METHODS: Blood pressure of bilateral ankles and upper extremities was measured at plain clinostatism with DINAMAP blood pressure monitor (GE Company). The ratio between average systolic pressure of lateral ankle and average systolic pressure of both upper extremities was regarded as ABI. The normal ABI was equal to or more than 0.9. If ABI < 0.9 occurred at one side, patients were diagnosed as PAD. On the second morning after hospitalization, blood was collected to measure fasting blood glucose (FBG), 2-hour postprandial blood glucose (PBG2h), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Among them, blood glucose, lipid and other biochemical markers were measured with enzyme chemistry assay and HbA1c was measured with HbA1c meter based on high liquid phase. Measurement data and enumeration data were compared with t test and Chi-square test, and multiple factors were dealt with Logistic regression analysis and multivariate linear regression analysis. MAIN OUTCOME MEASURES: Results of correlation between ABI and metabolic markers with multivariate linear regression analysis; risk factors of CI plus PAD with Logistic regression analysis; comparisons of metabolic markers between PAD and non-PAD patients. RESULTS: All 124 patients with acute CI were involved in the final analysis. ① Comparisons of metabolic markers: Levels of serum LDL-C and uric acid (UA) were higher of PAD patients than those of non-PAD patients (t =2.051 9, 3.339 1, P < 0.05); however, there were no significant differences among other metabolic markers (P > 0.05). ② Results of multivariate linear regression analysis: PBG2h, LDL-C and UA were obvious correlation with ABI of posterior tibial artery of lower limb and dorsal pedis artery (partial regression coefficient = -0.231 to -1.010, P < 0.05). ③ Risk factors of CI plus PAD with Logistic regression analysis: Age, smoking history, sum of CI focus (≥3) and LDL-C were independent risk factor of CI plus PAD (OR =1.524-5.422, P < 0.05-0.01). CONCLUSION: ① Levels of serum LDL-C and UA of patients with CI plus PAD are high. ② ABI of lower limbs is correlation with PBG2h, LDL-C and UA. In addition, measuring ABI is beneficial for early diagnosing PAD of lower limbs of patients who have poorly controlled blood glucose, abnormal lipid and poor renal function. ③ Age, LDL-C and sum of CI focus (≥3) are independent risk factors of CI plus PAD. It is of significance for screening non-PAD patients to evaluate risk degrees and prognosis and select therapeutic methods based on ABI measurement.
