期刊文献+
共找到45篇文章
< 1 2 3 >
每页显示 20 50 100
Influence of Seedling Age and Nitrogen Rates on Productivity of Rice (<i>Oryza sativa</i>L.): A Review 被引量:7
1
作者 Muhammad Mahran Aslam Muhammad Zeeshan +5 位作者 Ayesha Irum Muhammad Umair Hassan Saif Ali Rashid Hussain Pia Muhammad Adnan Ramzani Muhammad Farhan Rashid 《American Journal of Plant Sciences》 2015年第9期1361-1369,共9页
Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitroge... Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitrogen rates significantly affected its growth, development and yield components. Rice cultivars performed differently when transplanted in field at varying seedling ages depending upon their genetic makeup and adoptability to certain environmental conditions. Seedling age plays an important role in yield contributing parameters like number of productive tillers, panicle length, filled grains panicle-1 and 1000-kernel weight leading to higher paddy yield in different rice cultivars and hybrids. Nitrogen is required in huge quantity in rice production as it is an important constituent of plant parts and processes. Paddy yield increases significantly with the increase in nitrogen rate but after a certain limit yield starts decreasing. Keeping in view the significance of seedling age and nitrogen rates in different rice cultivars and hybrids, an effort has been made to review some research work already conducted and will be helpful to the researchers and scientists to plan future strategies. 展开更多
关键词 Hybrid RICE SEEDLING age Nitrogen rates PADDY Yield
下载PDF
Effects of indole-3-butyric acid and age of stem cuttings on root morphology,growth,and survival of Cornus sericea 被引量:1
2
作者 Sahari Inoue Chibuzo Ilogu Jean-Marie Sobze 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第2期433-440,共8页
Red osier dogwood(Cornus sericea L.),widely distributed throughout North America,is essential for wildlife,thus biodiversity.It is recommended for reclamation or revegetation of sites disturbed by oil and gas extracti... Red osier dogwood(Cornus sericea L.),widely distributed throughout North America,is essential for wildlife,thus biodiversity.It is recommended for reclamation or revegetation of sites disturbed by oil and gas extraction because it tolerates a wide range of soil types and high pH levels.Since germination of this species is extremely difficult with long stratification requirements and poor germination,cuttings facilitate propagation.In this study,to develop techniques to propagate the species from stem cuttings,four concentrations of indole-3-butyric acid(IBA)and two cutting ages previous year’s growth(PYG)and current year’s growth(CYG)were investigated for survival and growth.After 4 months,survival rate,height growth,and shoot biomass from PYG cuttings were enhanced with IB A.In contrast,IB A did not affect these parameters in CYG cuttings.Root morphology was significantly affected by IB A concentration and cutting age.IBA,at higher concentrations,increased root surface and length.Total root surface area and length of PYG cuttings were increased,which may facilitate the absorption of essential resources and consequently increase growth.The results indicate that increasing the concentration of IB A may be an effective way to have better plant survival and growth of previous year’s cuttings in red osier dogwood. 展开更多
关键词 Vegetative propagation IBA Chronological age Cornus sericea L. Survival rate
下载PDF
Predicting COVID-19 fatality rate based on age group using LSTM
3
作者 Zahra Ramezani Seyed Abbas Mousavi +3 位作者 Ghasem Oveis Mohammad Reza Parsai Fatemeh Abdollahi Jamshid Yazdani Charati 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2021年第12期564-574,共11页
Objective: To predict the daily incidence and fatality rates based on long short-term memory(LSTM) in 4 age groups of COVID-19 patients in Mazandaran Province, Iran.Methods: To predict the daily incidence and fatality... Objective: To predict the daily incidence and fatality rates based on long short-term memory(LSTM) in 4 age groups of COVID-19 patients in Mazandaran Province, Iran.Methods: To predict the daily incidence and fatality rates by age groups, this epidemiological study was conducted based on the LSTM model. All data of COVID-19 disease were collected daily for training the LSTM model from February 22, 2020 to April 10, 2021 in the Mazandaran University of Medical Sciences. We defined 4 age groups, i.e., patients under 29, between 30 and 49, between 50 and 59, and over 60 years old. Then, LSTM models were applied to predict the trend of daily incidence and fatality rates from 14 to 40 days in different age groups. The results of different methods were compared with each other.Results: This study evaluated 5 0826 patients and 5 109 deaths with COVID-19 daily in 20 cities of Mazandaran Province. Among the patients, 25 240 were females(49.7%), and 25 586 were males(50.3%). The predicted daily incidence rates on April 11, 2021 were 91.76, 155.84, 150.03, and 325.99 per 100 000 people, respectively;for the fourteenth day April 24, 2021, the predicted daily incidence rates were 35.91, 92.90, 83.74, and 225.68 in each group per 100 000 people. Furthermore, the predicted average daily incidence rates in 40 days for the 4 age groups were 34.25, 95.68, 76.43, and 210.80 per 100 000 people, and the daily fatality rates were 8.38, 4.18, 3.40, 22.53 per 100 000 people according to the established LSTM model. The findings demonstrated the daily incidence and fatality rates of 417.16 and 38.49 per 100 000 people for all age groups over the next 40 days. Conclusions: The results highlighted the proper performance of the LSTM model for predicting the daily incidence and fatality rates. It can clarify the path of spread or decline of the COVID-19 outbreak and the priority of vaccination in age groups. 展开更多
关键词 COVID-19 Long short-term memory model Incidence rate Fatality rate PREDICTION age classification
下载PDF
Age,growth,and mortality rate of the yellow goosefish Lophius litulon(Jordan,1902)in the Yellow Sea
4
作者 Yu SUN Chi ZHANG +1 位作者 Yongjun TIAN Yoshiro WATANABE 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第2期732-740,共9页
With the decline in the most fisheries resources in the Yellow Sea,the yellow goosefish Lophius litulon has increased in commercial and ecological importance in recent years.We studied the length distribution,length-w... With the decline in the most fisheries resources in the Yellow Sea,the yellow goosefish Lophius litulon has increased in commercial and ecological importance in recent years.We studied the length distribution,length-weight relationship,age composition,growth pattern,mortality,and exploitation rates of the yellow goosefish in the Yellow Sea.Total length(TL)of females and males ranged from 173 to 582 mm and 178 to 500 mm,respectively.The length-weight relationships were also estimated for females and males.Age classes from 2 to 4 years predominated in the samples.The von Bertalanffy growth function(VBGF),estimated based on non-linear least-squares methodology,showed significant differences between sexes.Females attained a greater estimated asymptotic total length(765 mm TL)compared to males(579 mm TL).The VBGF did not differ significantly between stocks of the northern Yellow Sea and the southern Yellow Sea.Estimated natural instantaneous mortality rate(M)ranged from 0.25/a to 0.33/a based on four age-and length-based methods.Total instantaneous mortality rate(Z)of total samples calculated by the age-based catch curve method was 0.591/a and the average fishing mortality(F)was 0.30/a.Estimated exploitation rate(E)was approximately 0.5,indicating that the population of L.litulon in the Yellow Sea may be sustainable.These results provide a reference for the present status of L.litulon and information for the management. 展开更多
关键词 Lophius litulon Yellow Sea age GROWTH mortality rate
下载PDF
AGE AND SITES-SPECIFIC PREVALENCE RATES OF PRECANCEROUS GASTRIC LESIONS AT A HIGH-RISK POPULATION OF STOMACH CANCER
5
作者 游伟程 William J.Blot +12 位作者 昌云生 李吉友 金懋林 谢玉泉 Robert W.Kneller 杨伯琴 韩忠祥 刘伟东 赵雷 张联 杨祖田 Joseph F.Fraumeni Jr 徐光炜 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1993年第2期8-13,共6页
A population-based screening for stomach cancer (SC) and its precancerous lesions was conducted in Linqu County, Shandong, China, one of the highest SC rates found in China and the world. An analysis of precancerous s... A population-based screening for stomach cancer (SC) and its precancerous lesions was conducted in Linqu County, Shandong, China, one of the highest SC rates found in China and the world. An analysis of precancerous stomach lesions revealed that chronic atrophic gastritis (CAG) was a universal common among people aged 35-64 (96-98%). For 52% and 20% of the residents in this age group had Intestinal metaplasia (IM) or dysplssia (DYS). These more advanced lesions were more pronounced in the antrum for both males and females. Age-specific prevalence rates in different anatomic locations sshowed that CAG, developed in the antrum, particularly along the lesser curvature earter than other sites and spread to fundus. IM and DYS accrued under the background of CAG with a leading time in the antrum than the other part of the stomach. Although CAG, IM and DYS prevalence rates were higher in the antrum than In the fundus, the prevalence rates showed a similar smoothly slope, a result of accumulated somatic geneticdamage, suggesting a similar biological response to the stimulation of initiator of carcinogenesis, promoter leading to progression to SC. 展开更多
关键词 Precancerous gastric lesions Prevalence rates age Anatomic locations
下载PDF
Aboveground carbon sequestration of Cunninghamia lanceolata forests:Magnitude and drivers
6
作者 Chen Wang Shuguang Liu +3 位作者 Yu Zhu Andrew R.Smith Ying Ning Deming Deng 《Forest Ecosystems》 SCIE CSCD 2024年第1期32-41,共10页
Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management optio... Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management options.How carbon density and sequestration in various Cunninghamia lanceolata forests,extensively cultivated for timber production in subtropical China,vary with biodiversity,forest structure,environment,and cultural factors remain poorly explored,presenting a critical knowledge gap for realizing carbon sequestration supply potential through management.Based on a large-scale database of 449 permanent forest inventory plots,we quantified the spatial-temporal heterogeneity of aboveground carbon densities and carbon accumulation rates in Cunninghamia lanceolate forests in Hunan Province,China,and attributed the contributions of stand structure,environmental,and management factors to the heterogeneity using quantile age-sequence analysis,partial least squares path modeling(PLS-PM),and hot-spot analysis.The results showed lower values of carbon density and sequestration on average,in comparison with other forests in the same climate zone(i.e.,subtropics),with pronounced spatial and temporal variability.Specifically,quantile regression analysis using carbon accumulation rates along an age sequence showed large differences in carbon sequestration rates among underperformed and outperformed forests(0.50 and 1.80 Mg·ha^(-1)·yr^(-1)).PLS-PM demonstrated that maximum DBH and stand density were the main crucial drivers of aboveground carbon density from young to mature forests.Furthermore,species diversity and geotopographic factors were the significant factors causing the large discrepancy in aboveground carbon density change between low-and high-carbon-bearing forests.Hotspot analysis revealed the importance of culture attributes in shaping the geospatial patterns of carbon sequestration.Our work highlighted that retaining largesized DBH trees and increasing shade-tolerant tree species were important to enhance carbon sequestration in C.lanceolate forests. 展开更多
关键词 Carbon density Carbon accumulation rate Forest age Spatial variation Cultural influence
下载PDF
A Review of Three Misconceptions about Age and L2 Learning(Marinova‐Todd,et al.,2000)and Comments on Stefka H.Marinova-Todd,D.Bradford Marshall,and Catherine E.Snow’s“Three Misconceptions About Age and L2 Learning.”(Hyltenstam&Abrahamsson,2001)
7
作者 何秋红 《海外英语》 2021年第2期90-91,107,共3页
Age has always been an important factor in studying second language acquisition.Marinova‐Todd points out three misconceptions about research in support of CPH and disputes the existence of a Critical Period in L2 lea... Age has always been an important factor in studying second language acquisition.Marinova‐Todd points out three misconceptions about research in support of CPH and disputes the existence of a Critical Period in L2 learning.Hyltenstam&Abrahamsson refutes Marinova‐Todd’s“three misconceptions”.By contrasting and comparing the views and evidence from the two papers,the present author analyzes the differences among various claims on the rate of learning and different brain organization,as well as the possible causes for the disagreements. 展开更多
关键词 Critical Period Hypothesis age rate of Learning Brain Organization Language Proficiency
下载PDF
The type, position and age effect on the cutting reproduction of Picea crassifolia and its rooting mechanism in the Qilian Mountains 被引量:5
8
作者 Jianjun Kang Wenzhi Zhao +3 位作者 Ming Zhao Guangyu Li Jiqiang Zhang Zhisheng Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第4期993-1002,共10页
Picea crassifolia Kom, a perennial arbor spe- cies is recognized as one of the most adaptable plants found to date in Qilian Mountains. To explore the cutting reproduction technology of P. crassifolia and reveal its r... Picea crassifolia Kom, a perennial arbor spe- cies is recognized as one of the most adaptable plants found to date in Qilian Mountains. To explore the cutting reproduction technology of P. crassifolia and reveal its rooting mechanism, cuttings of P. crassifolia with different cutting types (softwood, hardwood and root), positions (top, upper, middle and bottom) and ages (7, 10, 15, 20, 25 year-old) were cultivated in a field experiment. One- year old softwood and hardwood cuttings were collected from 7-, 10-, 15-, 20-, and 25 year-old healthy ortets to analyze the changes from endogenous hormones and organic nutrients. Results indicate that the softwood cut- tings (0.5-1.0 cm in diameter) from upper branches of 15 year-old ortets shows better growth performance by improving rooting indexes, including a significant increasein rooting rate and a decrease in basal rot rate. Concomi- tantly, increasing rooting quantity and root length also increased. It is noteworthy that the high rooting rate of P. crassifolia cuttings due to its ability to accumulate high concentrations of indole-3-acetic acid (IAA) and total carbon (TC) rather than abscisic acid (ABA) and total nitrogen (TN). The rooting rate was mainly regulated by the IAA/ABA and TC/TN ratio. In summary, our results suggest that the softwood cuttings (0.5-1.0 cm in diameter) from upper branches of 15 year-old P. crassifolia can be considered as an effective strategy to improve cutting rooting rate, and the IAA/ABA and TC/TN ratio was one of the main factors limiting the cutting rooting rate of P. crassifolia. 展开更多
关键词 Picea crassifolia Kom TYPE Positionand age effect Cutting reproduction Rooting rate HORMONES Organic substances
下载PDF
Effect of Lamb Age and in vitro Culture System of Oocytes on JIVET Technology 被引量:3
9
作者 Yangyi MAO Huidi LUO +7 位作者 Guanwu ZHANG Zhiwu WANG Peng ZHAO Jun LI Hongyu GUO Shenghua ZHOU Huihui GUO Chunyan LI 《Agricultural Biotechnology》 CAS 2019年第1期86-89,92,共5页
[Objectives] This study was conducted to investigate the effects of lamb age and in vitro culture system of oocytes on the results of juvenile in vitro embryo transfer( JIVET). [Methods]Ten Dorper × small-tailed ... [Objectives] This study was conducted to investigate the effects of lamb age and in vitro culture system of oocytes on the results of juvenile in vitro embryo transfer( JIVET). [Methods]Ten Dorper × small-tailed Han lambs aged 5 to 10 weeks were induced to superovulate via i. p. injection of pregnant mare's serum gonadotropin( PMSG). The oocytes were matured in basal maturation solution or modified maturation solution,which was prepared by adding 200 μmol/L cysteine to the basal maturation solution. Then,the oocytes were fertilized in fertilization medium I containing 2% estrus sheep serum( ESS) or fertilization medium II containing 3 mg/ml bull serum albumin( BSA). Finally,the number of oocytes,oocyte maturation rate and cleavage rate of the lambs of different ages were determined. [Results]The average number of oocytes recovered per lamb was( 111. 00 ± 16. 97),( 139. 50 ± 28. 99),( 108. 50 ± 17. 68) and( 42. 00 ± 11. 31) for5-,7-,8-and 10-week-old Dorper × small-tailed Han lambs,respectively. The number of oocytes obtained from 5-,7-and 8-week-old lambs was significantly higher than that from 10-week-old lambs( P < 0. 05),but there was no significant difference among 5-,7-and 8-week-old lambs( P > 0. 05). The maturation rate of oocytes cultured in modified maturation solution was 3. 64% higher than that in basal maturation solution. The cleavage rate of oocytes in fertilization medium I was very significantly higher than that in fertilization medium II( P < 0. 01). [Conclusions] The results of JIVET can be improved by harvesting oocytes from lambs aged 5-8 weeks,adding a certain amount of cysteine into oocyte maturation solution,and a certain amount of ESS into fertilization medium. 展开更多
关键词 JUVENILE LAMBS age OOCYTES In VITRO culture system JIVET Maturation rate Cleavage rate
下载PDF
Age and Body Size of the Shangcheng Stout Salamander Pachyhynobius shangchengensis(Caudata:Hynobiidae)from Southeastern China 被引量:2
10
作者 Jianli XIONG Jianping GOU +3 位作者 Yong HUANG Baowei ZHANG Hongtao REN Tao PAN 《Asian Herpetological Research》 SCIE CSCD 2020年第3期219-224,共6页
Age and body size a re critical for understanding life history evolution and ecology.In this study,the age and body size of the Shangcheng stout salamander,Pachyhynobius shangchengensis,from a population in Anhui Prov... Age and body size a re critical for understanding life history evolution and ecology.In this study,the age and body size of the Shangcheng stout salamander,Pachyhynobius shangchengensis,from a population in Anhui Province,China,were studied by skeletochronology.The mean age was 8.8±0.2(mean±SD)years in females and 9.6±0.2 in males and ranged 5-13 years for both sexes.The mean age was significantly different between sexes.The mean body size and mass were(100.21±0.91)mm and(31.76±0.73)g in females,and(105.31±1.23)mm and(37.14±1.12)g in males,respectively.Males were significantly larger and heavier than females,indicating sexual size dimorphism.There was a significant positive correlation among body size,body mass,and age,suggesting that the oldest individuals are larger and heavier.The growth rate in males was significantly higher than in females.The present study provides preliminary data on life-history traits which can be helpful for future studies of this species and other hynobiid salamanders. 展开更多
关键词 age structure growth rate life history SKELETOCHRONOLOGY
下载PDF
Minimum Bedrock Exposure Ages and Their Implications:Larsemann Hills and Neighboring Bolingen Islands,East Antarctica 被引量:2
11
作者 HUANG Feixin LI Guangwei +5 位作者 LIU Xiaohan KONG Ping JU Yitai David FINK FANG Aimin YU Liangjun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第3期543-548,共6页
Considerable controversy exists over whether or not extensive glaciation occurred during the global Last Glacial Maximum(LGM) in the Larsemann Hills.In this study we use the in situ produced cosmogenic nuclide ^(10... Considerable controversy exists over whether or not extensive glaciation occurred during the global Last Glacial Maximum(LGM) in the Larsemann Hills.In this study we use the in situ produced cosmogenic nuclide ^(10)Be(half life 1.51 Ma) to provide minimum exposure ages for six bedrock samples and one erratic boulder in order to determine the last period of deglaciation in the Larsemann Hills and on the neighboring Bolingen Islands.Three bedrock samples taken from Friendship Mountain(the highest peak on the Mirror Peninsula,Larsemann Hills;~2 km from the ice sheet) have minimum exposure ages ranging from 40.0 to 44.7 ka.The erratic boulder from Peak 106(just at the edge of the ice sheet) has a younger minimum exposure age of only 8.8 ka.The minimum exposure ages for two bedrock samples from Blundell Peak(the highest peak on Stornes Peninsula,Larsemann Hills;~2 km from the ice sheet) are about 17 and 18 ka.On the Bolingen Islands(southwest to the Larsemann Hills;~10 km from the ice sheet),the minimum exposure age for one bedrock sample is similar to that at Friendship Mountain(i.e.,44 ka).Our results indicate that the bedrock exposure in the Larsemann Hills and on the neighboring Bolingen Islands commenced obviously before the global LGM(i.e.,20-22 ka),and the bedrock erosion rates at the Antarctic coast areas may be obviously higher than in the interior land. 展开更多
关键词 east Antarctica Larsemann Hills Bolingen Islands 1~Be exposure age erosion rate
下载PDF
Accumulation and geochemical evidence for the Little Ice Age episode in eastern Antarctica 被引量:1
12
作者 ChuanJin Li JiaWen Ren +5 位作者 CunDe Xiao MingHu Ding AiHong Xie ZhiHeng Du XiangYu Ma DaHe Qin 《Research in Cold and Arid Regions》 CSCD 2019年第1期50-61,共12页
Data on accumulation and concentration of chemical compounds recorded in an essentially unexplored area(Dome Argus)of the Indian Ocean sector of eastern Antarctica during the past 2,680 years(680 B.C. to 1999 A.D.) ar... Data on accumulation and concentration of chemical compounds recorded in an essentially unexplored area(Dome Argus)of the Indian Ocean sector of eastern Antarctica during the past 2,680 years(680 B.C. to 1999 A.D.) are presented. During the first 1, 700 years(680 B. C. to 1000 A. D.), the accumulation data shows a slightly decreasing trend, while chemical ions appear to be stable, representing a stable climatic condition. An intensive increasing trend of the accumulation occurred during the 12^(th) to 14^(th) century. The period from 15^(th) to 19^(th) century was characterized by a rapid reducing accumulation and concentrations of volatile compounds suffering post-depositional loss linked to sparse precipitation amount,which was temporally consistent with the Little Ice Age(LIA) episode. Comparison between observed accumulation rates with other eastern Antarctic ice cores show a consistent decreasing trend during LIA, while sea salt and dust-originated ions increased due to sea ice extent and intensified atmospheric transportation. Distribution of volcanic originated sulfate over the Antarctic continent show a significant change during the 15^(th) century, coincident with the onset of the LIA. These results are important for the assessment of Antarctic continent mass balance and associated interpretation of the Dome A deep ice core records. 展开更多
关键词 ACCUMULATION rates sea SALT chemical compounds LITTLE Ice age EASTERN ANTARCTICA
下载PDF
Frequency of Monthly Ejaculation at Sexual Intercourse, DNA Fragmentation Index and Fertilization Rate among Sperm Donors and Fertility-Challenged Men in Sub-Saharan Africa: Paper 1 被引量:1
13
作者 Abayomi B. Ajayi Bamgboye M. Afolabi +6 位作者 Victor D. Ajayi Ifeoluwa O. Oyetunji Adedamilola Atiba Seun Saanu Ayodeji T. Adeoye Joy Ehichioya Ibukun I. Ayelehin 《Open Journal of Urology》 2019年第11期181-194,共14页
Introduction: In humans, the ideal ejaculation frequency depends on age, exercise and sexual potential. Natural ejaculation frequency balances the testosterone levels in the body. Materials and Methods: Semi-structure... Introduction: In humans, the ideal ejaculation frequency depends on age, exercise and sexual potential. Natural ejaculation frequency balances the testosterone levels in the body. Materials and Methods: Semi-structured questionnaire was used to collect information from subjects. Semen samples were collected from sperm donors and sub-fertile men who presented for infertility challenges. Processing and analysis of semen samples were done according to World Health Organization guidelines. Sperm DNA fragmentation was evaluated using the Halosperm&#174;?kit. Results: A total of 114 subjects, including 19 sperm donors and 95 sub-fertile males were studied. There was a significant difference (t =?&#8722;5.96, P-value = 0.00001) in the mean [±sd] age of sperm donors (30.8 [8.1]) and that of sub-fertile men (42.3 [76]). There was a significant difference (t=?&#8722;4.10, P-value = 0.0005) in the mean monthly ejaculation during sexual intercourse (MESI) among sperm donors with DNA fragmentation index &#8722;2.20, P-value = 0.02) in MESI among sub-fertile men aged ≥40 years (8.9 [4.6]) than among those aged &#8722;0.67, SE = 0.28, t = &#8722;2.40, P-value = 0.02, 95% CI: &#8722;1.24,?&#8722;0.10). Conclusion: In men < 40 years, fewer MESI did not worsen the DFI. A higher number of professionals such as doctors, lawyers and engineers, reported lower monthly frequency of sexual ejaculations compared to entrepreneurs. Entrepreneurs and non-smokers had the highest frequencies of MESI. 展开更多
关键词 MONTHLY Sexual EJACULATION rate DNA Fragmentation INDEX Male INFERTILITY age Group Body Mass INDEX Social HABITS Black AFRICANS
下载PDF
Long-Term Monitoring and Analysis of Age-Related Changes on Autonomic Nervous Function
14
作者 Kenichi Itao Makoto Komazawa +1 位作者 Zhiwei Luo Hiroyuki Kobayashi 《Health》 2017年第2期323-344,共22页
This study used a small wearable heart rate sensor to monitor the daily autonomic function of 600 subjects from across all age groups over a prolonged period of time. The results indicated that the LF/HF ratio (Heart ... This study used a small wearable heart rate sensor to monitor the daily autonomic function of 600 subjects from across all age groups over a prolonged period of time. The results indicated that the LF/HF ratio (Heart Rate Variability, LF: frequencies between 0.04 Hz - 0.15 Hz, HF: frequencies between 0.15 Hz - 0.4 Hz) an indicator of balance in the autonomic nervous system, tended to peak for subjects in their 40’s and decline thereafter. This conceivably may be partially due to the causes for concern and stress changing and/or declining for the group aged 50-plus. A decline in diurnal variation of autonomic nervous activity was also exhibited in subjects aged 50 and up, showing a tendency for decline in the function of rising sympathetic nerve activity particularly in the morning. It is conceivable that this stems from a decline in the responsiveness of the autonomic nervous system. Subjects in the 50-plus group furthermore exhibited a tendency for declining variation in autonomic nervous activity between sleeping and waking hours. This phenomenon was consistent with the tendency for there to be a rise in wake after sleep onset coupled with a decline in slow-wave sleep in middle- to old-age. 展开更多
关键词 HEART rate VARIABILITY AUTONOMIC Nervous System Stress age CIRCADIAN RHYTHM SLEEP
下载PDF
Causal relationships between survival rates, dietary and lifestyle habits, socioeconomic status and physical, mental and social health in elderly urban dwellers in Japan: A chronological study
15
作者 Tanji Hoshi Motoyuki Yuasa +3 位作者 Suwen Yang Sugako Kurimori Naoko Sakurai Yoshinori Fujiwara 《Health》 2013年第8期1303-1312,共10页
Life expectancy was well known to associate with lifestyle habits, socioeconomic condition, and three health-related dimensions (physical, mental and social health status). However, the causal effect relationship amon... Life expectancy was well known to associate with lifestyle habits, socioeconomic condition, and three health-related dimensions (physical, mental and social health status). However, the causal effect relationship among these variables remains unclear. The purpose of this study was to determine the causal relationships among health and life conditions, socioeconomic status, dietary and lifestyle habits and three health-related dimensions in elderly urban dwellers in Tokyo, Japan. Of 16,462 eligible elderly individuals aged 65 years and older, 13,195 participants responded to the questionnaire survey conducted in September 2001 (a response rate of 80.2%). A follow-up survey was conducted in September 2004 and a total of 8162 survivors were followed until the end of August 2007 through the municipal resident's registry. Exploratory factor analysis defined five latent variables based on the 13 observed variables. From a cross-lagged effects variation model using structural equation modeling, causal relationships were analyzed using longitudinal data obtained at the 2001 and 2004 survey and the number of survival days between 2004 and 2007. After estimating a best-fit model, we discovered that health and life conditions were not determined by current dietary and lifestyle habits, which many studies showed. However, the conditions were more directly affected by three health-related dimensions three years earlier, and indirectly affected by educational attainment and previous annual income as well. The current model suggests that it might be of great importance for elderly individuals to emphasize the maintenance of psychological well being, physical activity, social communication and participation, as well as income, rather than focusing on improvements in diet and health-related lifestyles per se. 展开更多
关键词 Survival rate Food HABITS Life Style SOCIOECONOMIC Status aged JAPAN
下载PDF
Growth Hormone Treatment, Cardiovascular Risk and Autonomic Maturation in Children and Adolescents with Growth Hormone Deficiency or Born Small for Gestational Age
16
作者 Reiner Buchhorn Christian Willaschek 《Open Journal of Pediatrics》 2020年第1期12-29,共18页
Introduction: The impact of growth hormone therapy in children with short stature on cardiovascular prognosis seems to be unpredictable from big databases. The enhanced cardiovascular risk in this group of patients ma... Introduction: The impact of growth hormone therapy in children with short stature on cardiovascular prognosis seems to be unpredictable from big databases. The enhanced cardiovascular risk in this group of patients may be related to adverse autonomic imprinting by early life stress. Autonomic dysfunction and possible effects of growth hormone therapy on the autonomic nervous system can be measured easily by calculating heart rate variability (HRV) from Holter electrocardiogram monitoring. Methods: We performed HRV analysis prior to growth hormone therapy (N = 33), within the first year of growth hormone therapy between 4 and 10 years of age (N = 19), at least a further HRV measurement between 10 and 15 years (N = 30). Additional measurements were performed before and after cessation of growth hormone therapy (N = 14). Data were compared to untreated pediatric patients with short stature and to age matched healthy controls. Results: Untreated patients with short stature due to growth hormone deficiency or intrauterine growth restriction in early childhood have significantly increased heart rates most of all at night and concomitantly reduced global HRV indicated as Standard Deviation of Normal to Normal Intervals (SDNN). Growth hormone treated adolescents and the untreated patients with short stature show significantly elevated mean heart rates and concomitantly reduced vagus activities measured as reduced Route Mean Square Standard Deviation (RMSSD). After cessation of growth hormone treatment SDNN significantly increases and heart rate decreases to normal values in formerly treated patients with catch-up growth. Conclusion: There is a comparable autonomic dysfunction in treated and untreated children with short stature as an indicator for enhanced cardiovascular risk. After cessation of growth hormone therapy, we found a significant improvement of reduced HRV to normal values. 展开更多
关键词 Growth HORMONE Cardiovascular Risk Short STATURE Small for GESTATIONAL age Heart rate Variability AUTONOMIC Nervous System ADHD
下载PDF
Partial Weaning at Six Weeks of Age Reduces Biting among Mink Kits(Neovison Vison)
17
作者 Tove Norgaard Clausen Peter Foged Larsen 《Open Journal of Animal Sciences》 2015年第2期71-76,共6页
Recent studies have demonstrated that postponed weaning age from 6 weeks to 8 weeks in mink increases the number of bites among mink kits. Therefore, a series of studies have been conducted in order to quantify effect... Recent studies have demonstrated that postponed weaning age from 6 weeks to 8 weeks in mink increases the number of bites among mink kits. Therefore, a series of studies have been conducted in order to quantify effects of weaning age on mortality, number of bites and growth rates in mink kits weaned at 42 and 56 days after birth during two consecutive breeding seasons. Partial weaning of large litters on Day 42 reduced the number of mink kits and litters with bites from an average frequency of 1.6% to 1.0% for kits and 8.1% to 5.1% for litters and increased growth rate of male kits. These results are highly important for ensuring optimal welfare in mink production, and we recommend that partial weaning (dividing) of large litters should be considered in practical mink farming in the future. 展开更多
关键词 age of Weaning BITES MORTALITY Growth rate
下载PDF
Study on Photosynthetic Characteristics of Hybrid Mulberry in Autumn under Herbaceous Cultivation
18
作者 Fangying XU Jinjian YU +2 位作者 Huaqiang DONG Dezhong CHEN Jianzhong TAN 《Agricultural Biotechnology》 CAS 2023年第5期19-21,25,共4页
[Objectives]This study was conducted to clarify the physiological mechanism of growth of hybrid mulberry after autumn cutting in herbaceous cultivation.[Methods]The net photosynthetic rate(Pn),stomatal conductance(Gs)... [Objectives]This study was conducted to clarify the physiological mechanism of growth of hybrid mulberry after autumn cutting in herbaceous cultivation.[Methods]The net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci)and transpiration rate(Tr)of leaves were measured under different treatment conditions using a Li-6400XT portable photosynthetic measurement system.[Results]After harvest of mulberry shoots in autumn,leaf Pn decreased with the extension of branch and leaf growth time,while Gs,Ci and Tr showed a trend of first increasing and then decreasing.The Pn was affected by factors such as leaf positions,mulberry varieties,cutting,and fertilization,which was manifested by the 6 th to 10 th mature leaves>the 2 nd to 4 th tender leaves,‘Nongsang 14’>hybrid mulberry,intermediate cut>uncut,and normal fertilization>no fertilization,all showing significant differences(P<0.05).Combined with the results of Gs,Ci and Tr measurements,it was found that the changes in leaf Pn were mainly related to non-stomatal factors.Timely cutting and harvesting during summer and autumn could significantly improve the photosynthetic rate of mulberry leaf,which was beneficial for extending the late autumn growth period of hybrid mulberry under herbaceous cultivation.[Conclusions]This study provides a theoretical reference for mulberry shoot harvesting techniques in summer and autumn. 展开更多
关键词 Hybrid mulberry Herbaceous cultivation Harvest of mulberry shoots Photosynthetic rate Leaf age
下载PDF
施氮量·密度和苗龄对稻田免耕油菜苗期干物质积累的影响(英文) 被引量:5
19
作者 艾复清 张帆 +1 位作者 舒中兵 樊宁 《Agricultural Science & Technology》 CAS 2008年第6期93-96,107,共5页
[Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three ... [Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three factors, the 310 scheme was designed to study the effects of nitrogen application rate, density and seedling age on dry matter accumulation of no-tillage rape in seedling stage. [Result] With the increase of nitrogen application rate, density and seedling age, the dry matter content appeared like a parabola, increasing firstly and then declining. The change of nitrogen application rate caused greater influence than that of density and seedling age; the interaction effects between nitrogen application rate and density were greater than that between nitrogen application rate and seedling age as well as between density and seedling age. [Conclusion] Considered comprehensively, the dry matter content of no-tillage rape in seedling stage reached the highest level (4 768.2 kg/hm2) when the nitrogen application rate, the density and the seedling age were 195 kg/hm2, 93 000 plants/hm2 and 33 d, respectively. 展开更多
关键词 Nitrogen application rate Density SEEDLING age Dry matter accumulation SEEDLING NO-TILLage RAPE
下载PDF
鄂温克族与鄂伦春族的群体遗传学研究(续) 被引量:3
20
作者 陈良忠 杜若甫 《人类学学报》 1983年第4期380-389,共10页
本次调查采印了645名鄂温克族和424名鄂伦春族中、小学生和部分牧民、猎民的指纹和掌纹。观察了各型指纹出现率、指纹总嵴数、atd角和掌褶纹等指标。 1.各型指纹出现率 弓(A)、尺侧箕(L^u)、桡侧箕(L^r)和斗(W)的出现频率见表11。额左... 本次调查采印了645名鄂温克族和424名鄂伦春族中、小学生和部分牧民、猎民的指纹和掌纹。观察了各型指纹出现率、指纹总嵴数、atd角和掌褶纹等指标。 1.各型指纹出现率 弓(A)、尺侧箕(L^u)、桡侧箕(L^r)和斗(W)的出现频率见表11。额左旗和陈旗鄂温克人中斗多于箕,与汉族相似。有些指纹型在某个手指上较为多见。 展开更多
关键词 Human population genetics EWENKI NATIONALITY OROQEN NATIONALITY rate of consanguineous marriages Anthropometry BLOOD groups DERMATOGLYPHICS BLOOD pre-ssure Taste threshold for phenylthiocarbamide MENARCHE age
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部