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Litter production and leaf nutrient concentration and remobilization in response to climate seasonality in the central Amazon
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作者 Ricardo Antonio Marenco Saul Alfredo Antezana-Vera +1 位作者 Daniela Pereira Dias Luiz Antonio Candido 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期131-141,共11页
Litterfall is the largest source of nutrients to for-est soils of tropical rainforests.However,variability in lit-terfall production,nutrient remobilization,and changes in leaf nutrient concentration with climate seas... Litterfall is the largest source of nutrients to for-est soils of tropical rainforests.However,variability in lit-terfall production,nutrient remobilization,and changes in leaf nutrient concentration with climate seasonality remain largely unknown for the central Amazon.This study meas-ured litterfall production,leaf nutrient remobilization,and leaf area index on a forest plateau in the central Amazon.Litterfall was measured at monthly intervals during 2014,while nitrogen,phosphorus,potassium,calcium and mag-nesium concentrations of leaf litter and canopy leaves were measured in the dry and rainy seasons,and remobilization rates determined.Leaf area index was also recorded in the dry and rainy seasons.Monthly litterfall varied from 33.2(in the rainy season)to 87.6 g m^(-2) in the dry season,while leaf area index increased slightly in the rainy season.Climatic seasonality had no effect on concentrations of nitrogen,calcium,and magnesium,whereas phosphorous and potassium responded to rainfall seasonality oppositely.While phosphorous increased,potassium decreased during the dry season.Over seasons,nitrogen,potassium,and phosphorous decreased in leaf litter;calcium increased in leaf litter,while magnesium remained unaffected with leaf aging.Regardless,the five nutrients had similar remobilization rates over the year.The absence of climate seasonality on nutrient remobilization suggests that the current length of the dry season does not alter nutrient remobilization rates but this may change as dry periods become more prolonged in the future due to climate change. 展开更多
关键词 THROUGHFALL Nutrient cycling Climatic seasonality Leaf mass per area
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THE THRESHOLD DYNAMICS OF A WATERBORNE PATHOGEN MODEL WITH SEASONALITY IN A POLLUTED ENVIRONMENT
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作者 Shun ZHI Youhui SU +1 位作者 Hongtao NIU Lizhong QIANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第6期2165-2189,共25页
This paper concentrates on the dynamics of a waterborne pathogen periodic PDE model with environmental pollution.For this model,we derive the basic reproduction number R0and establish a threshold type result on its gl... This paper concentrates on the dynamics of a waterborne pathogen periodic PDE model with environmental pollution.For this model,we derive the basic reproduction number R0and establish a threshold type result on its global dynamics in terms of R0,which predicts the extinction or persistence of diseases.More precisely,the disease-free steady state is globally attractive if R_(0)<1,while the system admits at least one positive periodic solution and the disease is uniformly persistent if R_(0)>1.Moreover,we carry out some numerical simulations to illustrate the long-term behaviors of solutions and explore the influence of environmental pollution and seasonality on the spread of waterborne diseases. 展开更多
关键词 waterborne pathogen environmental pollution the basic reproduction number seasonality
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Degree of shade tolerance shapes seasonality of chlorophyll, nitrogen and phosphorus levels of trees and herbs in a temperate deciduous forest
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作者 Jiajia Zeng Fan Liu +5 位作者 Yuan Zhu Jiayi Li Ying Ruan Xiankui Quan Chuankuan Wang Xingchang Wang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第4期60-72,共13页
Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types withi... Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types within the canopy are poorly quantified.In this study,the seasonality of leaf chlorophyll,nitrogen(N),and phosphorus(P)were quantified vertically along the canopy of four major tree species and two types of herbs in a temperate deciduous forest.The role of shade tolerance in shaping the seasonal variation and vertical differentiation was examined.During the entire season,chlorophyll content showed a distinct asymmetric unimodal pattern for all species,with greater chlorophyll levels in autumn than in spring,and the timing of peak chlorophyll per leaf area gradually decreased as shade tolerance increased.Chlorophyll a:b ratios gradually decreased with increasing shade tolerance.Leaf N and P contents sharply declined during leaf expansion,remained steady in the mature stage and decreased again during leaf senescence.Over the seasons,the lower canopy layer had significantly higher chlorophyll per leaf mass but not chlorophyll per leaf area than the upper canopy layer regardless of degree of shade tolerance.However,N and P per leaf area of intermediate shade-tolerant and fully shade-tolerant tree species were significantly higher in the upper canopy than in the lower.Seasonal variations in N:P ratios suggest changes in N or P limitation.These findings indicate that shade tolerance is a key feature shaping inter-specific differences in leaf chlorophyll,N,and P contents as well as their seasonality in temperate deciduous forests,which have significant implications for modeling leaf photosynthesis and ecosystem production. 展开更多
关键词 Leaf traits Leaf nutrients Seasonal variations CHLOROPHYLL Nitrogen Phosphorus Shade tolerance Canopy layers
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Extended spectrum cephalosporin(ESC)resistant Escherichia coli:trends and seasonality in the Netherlands from 2014 to 2022
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作者 Michael S.M.Brouwer Eduardo de Freitas Costa +2 位作者 Anita Dame-Korevaar Adam P.Roberts Kees T.Veldman 《Science in One Health》 2024年第1期215-220,共6页
Background:Antimicrobial resistance(AMR)in livestock and the environment likely contribute to the prevalence of AMR in humans with potential detrimental effects on human health.As such,annual mandatory monitoring of A... Background:Antimicrobial resistance(AMR)in livestock and the environment likely contribute to the prevalence of AMR in humans with potential detrimental effects on human health.As such,annual mandatory monitoring of AMR in livestock occurs within the European Union(EU),according to harmonised methods.Extended-spectrum cephalosporins-resistant(ESC-resistant)Escherichia coli,including extended-spectrumβ-lactamases(ESBL),AmpCβ-lactamases(AmpC)and carbapenemase producing E.coli,are considered of particular importance and are therefore included in the monitoring program.Methods:Using results from the annual monitoring of ESC-resistant E.coli from 2014-2022,trends in prevalence per animal sector were determined over the complete time period,as well as potential seasonal effects.Results:During these nine years,significant changes were observed in the prevalence of ESC-resistant E.coli,in broilers,dairy cattle and veal calves,while no changes in prevalence were seen in slaughter pigs.Furthermore,the prevalence of ESC-resistant E.coli is positively correlated with warmer seasons(summer and autumn)for both dairy cattle and veal calves,while no associations were found for broilers and slaughter pigs.While temperature itself may play a role in the prevalence of ESC-resistant E.coli,other factors affecting the selective landscape,such as antibiotic usage,will also play a role.Conclusion:A combined analysis of antimicrobial usage and prevalence of ESC-resistant E.coli through the year,both in livestock and human samples,would be an interesting follow-up of this study. 展开更多
关键词 AMR Livestock Season ESBL Extended-spectrum cephalosporin-resistant
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Diagnostic Study on Seasonality and Interannual Variability of Wind Field 被引量:15
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作者 薛峰 曾庆存 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1999年第4期537-543,共7页
Based on NCEP/ NCAR reanalysis data during 1980-1994, seasonally and interannual variability of the horizontal wind field are studied. It is shown that: (1) In the lower troposphere, there exist regions with maximum o... Based on NCEP/ NCAR reanalysis data during 1980-1994, seasonally and interannual variability of the horizontal wind field are studied. It is shown that: (1) In the lower troposphere, there exist regions with maximum of seasonally in the tropics, the subtropics and high latitudes, which is called the tropical, subtropical and temperate-frigid monsoon region respectively. In the upper troposphere, the subtropical monsoon combines with the tropical monsoon as a nonseparably planetary monsoon system. In the stratosphere, there is a belt with very large seasonality in each hemisphere caused by the inversely seasonal circulation and by the establishment and collapse of the night jet. (2) Seasonal variation of the large-scale monsoon may generally be attributed to that of the zonal wind, however, seasonal variation of the meridional wind is of great importance in East Asian monsoon region. (3) In monsoon region, interannual variability of the atmospheric general circulation is closely related to seasonal variation of monsoon, while in the tropical Pacific, it may considerably be influenced by the external factors such as sea surface temperature (SST) anomalies associated with El Nino or La Nina event. Moreover, interannual variability undergoes a pronounced annual cycle. 展开更多
关键词 Atmospheric general circulation seasonality Interannual variability MONSOON
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Seasonality of Interannual Inter-hemispheric Oscillations over the Past Five Decades 被引量:14
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作者 管兆勇 卢楚翰 +1 位作者 梅士龙 丛菁 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第5期1043-1050,共8页
Air mass is inter-hemispherically redistributed, leading to an interesting phenomenon known as the Inter-Hemispheric Oscillation (IHO). In the present article, the seasonality of the interannual IHO has been examine... Air mass is inter-hemispherically redistributed, leading to an interesting phenomenon known as the Inter-Hemispheric Oscillation (IHO). In the present article, the seasonality of the interannual IHO has been examined by employing monthly mean reanalyses from NCEP/NCAR, EAR40, and JRA25 for the period of 1958–2006. It is found that the IHO indices as calculated from different reanalyses are generally consistent with each other. A distinct seesaw structure in all four seasons between the northern and southern hemispheres is observed as the IHO signature in both the surface air pressure anomalies (SAPAs) and the leading EOF component of the anomalous zonal mean quantities. When the SAPAs are positive (negative) in the northern hemisphere, they are negative (positive) in the southern hemisphere. Large values of SAPAs are usually observed in mid- and high-latitude areas in all but the solstice seasons. In boreal summer and winter, relatively stronger perturbations of IHO-related SAPA are found in the Asian monsoon region, which shows a large difference from the status in boreal spring and fall. This suggests that seasonal mean monsoon activity is globally linked via air mass redistribution globally on interannual timescales, showing a very interesting linkage between monsoons and the IHO in the global domain. In all seasons, large values of SAPA always exist over the Antarctic and the surrounding regions, implying a close relation with Antarctic oscillations. 展开更多
关键词 inter-hemispheric oscillation seasonality interannual variability surface air pressure anomaly
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Seasonality of the Lagged Relationship between ENSO and the Northern Hemispheric Polar Vortex Variability 被引量:4
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作者 Ren Rong-Cai 《Atmospheric and Oceanic Science Letters》 2012年第2期113-118,共6页
<Abstract>This paper reports the seasonal feature of the relationship between ENSO and the stratospheric Polar Vortex Oscillation (PVO) variability in the Northern Hemisphere.It is shown that the lagged ENSO-PVO... <Abstract>This paper reports the seasonal feature of the relationship between ENSO and the stratospheric Polar Vortex Oscillation (PVO) variability in the Northern Hemisphere.It is shown that the lagged ENSO-PVO coupling relationship exhibits distinct seasonal feature,due to the strong seasonality of PVO and ENSO.Specifically,the PVO variability not only during winter,but also in autumn and spring months,is significantly correlated with ENSO anomalies leading by seasons;however,no significant effect of ENSO is found on the PVO variability in winter months of November and February.Although a significant ENSO effect is primarily observed when ENSO leads PVO by about one year,a significant correlation is also found between PVO in the following spring months (M +1 A +1) and ENSO anomalies in the previous autumn (A-1 S-1 O- 1 N -1) when ENSO anomalies lead by about 18 months.The significant correlation between PVO in various seasons and the corresponding ENSO anomalies leading by seasons could be explicitly verified in most of the individual years,confirming that the lagged ENSO effect can largely modulate the seasonal timescale variability of PVO.Moreover,the composite spatial patterns of the zonal-mean temperature anomalies further show that the ENSO effect on the PVO in various seasons is related to the interannual variability of the seasonal timescale PVO events. 展开更多
关键词 seasonality ENSO STRATOSPHERE polar vortex
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Seasonality of the Interaction between Convection over the Western Pacific and General Circulation in the Northern Hemisphere 被引量:2
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作者 胡增臻 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1997年第4期110-122,共13页
The seasonality of the interaction between convection over the western Pacific and general circulation in the Northern Hemisphere (NH) is analyzed in the present paper with singular value decomposition (SVD) and empir... The seasonality of the interaction between convection over the western Pacific and general circulation in the Northern Hemisphere (NH) is analyzed in the present paper with singular value decomposition (SVD) and empirical orthogonal function (EOF) analysis approaches, based on 500 hPa monthly mean geopotential height data and high-cloud amount data. The analyses demonstrate that coupled dominant patterns in the interaction between the convection over the western Pacific and the general circulation in NH are different in various seasons. In spring, the convection over the western Pacific is closely related with the western Atlantic (WA) and North Pacific (NP) like patterns of the general circulation in NH, and some associations between the WA and NP like patterns and the El Ni o /Southern Oscillation (ENSO) cycle are also existed. The Pacific Japan (PJ) pattern is the dominant pattern in the interaction between the interannual variabilities of the convection over the western Pacific and the general circulation in NH summer. The WA like pattern and 3-4 year period oscillation are also relatively obvious for the summer case. In autumn, the convection over the western Pacific is closely linked with the Eurasian (EU) like pattern and the Atlantic oscillation in the general circulation in NH, it is suggested that in autumn the variation of convective activity over the western Pacific is largely affected by the general circulation anomaly (cold air from high latitudes ) through EU like teleconnection pattern. Abrupt change happened by the end of 1980′s in the autumn interaction. The strong interaction between the western Pacific (WP) and EU like patterns in the general circulation in NH and the convection over the western Pacific and a linear trend of increasing of this interaction are also suggested in winter. It is also demonstrated that the interaction in summer and winter is stronger than in the transition seasons (spring and autumn). 展开更多
关键词 seasonality INTERACTION Convection over the western Pacific General circulation in the Northern Hemisphere
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Seasonality and causes of the Yellow Sea Warm Current 被引量:1
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作者 崔茂常 胡敦欣 莫军 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第3期265-270,共6页
To study the seasonality and causes of the Yellow Sea Warm Current (YSWC) in detail, rotated empirical orthogonal function (REOF) and extended associate pattern analysis are adopted with daily sea surface salinity (SS... To study the seasonality and causes of the Yellow Sea Warm Current (YSWC) in detail, rotated empirical orthogonal function (REOF) and extended associate pattern analysis are adopted with daily sea surface salinity (SSS), sea surface temperature (SST) and sea surface height (SSH) datasets covering 1126 days from American Navy Experimental Real-Time East Asian Seas Ocean Nowcast System in the present paper. Results show that in the Yellow and East China Seas, the YSWC is a mean barotropic flow as compensation of winter-monsoon-driven surface currents, which has been directly observed. When East Asia winter monsoon weakens, so do the meridional pressure gradient of the surface seawater and the YSWC, while the transversal pressure gradient changes rather slowly that results in the YSWC left turning. In addition, there is southward mean flow compensation of summer-monsoon-driven surface currents, which actually was also directly observed. 展开更多
关键词 seasonality YSWC REOF extended associate pattern analysis
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Quantifying the Spatial Characteristics of the Moisture Transport Affecting Precipitation Seasonality and Recycling Variability in Central Asia 被引量:1
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作者 Linhao ZHONG Lijuan HUA +2 位作者 Zhaohui GONG Yao YAO Lin MU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第6期967-984,共18页
Moisture contribution and transport pathways for Central Asia(CA)are quantitatively examined using the Lagrangian water cycle model based on reanalysis and observational data to explain the precipitation seasonality a... Moisture contribution and transport pathways for Central Asia(CA)are quantitatively examined using the Lagrangian water cycle model based on reanalysis and observational data to explain the precipitation seasonality and the moisture transport variation during 1979-2015.Westerly-related(northwesterly and westerly)transport explains 42%of CA precipitation and dominates in southwest CA,where precipitation is greatest in the cold season.Southeast CA,including part of Northwest China,experiences its maximum precipitation in the warm season and is solely dominated by southerly transport,which explains about 48%of CA precipitation.The remaining 10%of CA precipitation is explained by northerly transport,which steadily impacts north CA and causes a maximum in precipitation in the warm season.Most CA areas are exposed to seasonally varying moisture transport,except for southeast and north CA,which are impacted by southerly and northerly transport year-round.In general,the midlatitude westerlies-driven transport and the Indian monsoon-driven southerly-related transport explain most of the spatial differences in precipitation seasonality over CA.Moreover,the contribution ratio of local evaporation in CA to precipitation exhibits significant interdecadal variability and a meridionally oriented tripole of moisture transport anomalies.Since the early 2000s,CA has experienced a decade of anomalously low local moisture contribution,which seems jointly determined by the weakened moisture contribution from midlatitudes(the Atlantic,Europe,and CA itself)and the enhanced contribution from high latitudes(West Siberia and the Arctic)and tropical areas(South Asia and the Indian Ocean). 展开更多
关键词 Central Asia precipitation seasonality recycling ratio moisture transport dynamical recycling model interdecadal variability
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Extrauterine Pregnancy: A Nine-Year Review of Incidence, Seasonality and Management at a Tertiary Hospital in Southern Ghana 被引量:1
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作者 Evans Kofi Agbeno Anthony Amanfo Ofori +4 位作者 Joseph Osarfo Doughan Samuel Joseph Amoah Adu Sebastien Ken-Amoah Wisdom Klutse Azanu 《Open Journal of Obstetrics and Gynecology》 2020年第2期264-274,共11页
Introduction: Most cases of extrauterine pregnancies present in the ruptured state in low-resource settings and patients with haemodynamic instability risk mortality without swift intervention. An idea of when ectopic... Introduction: Most cases of extrauterine pregnancies present in the ruptured state in low-resource settings and patients with haemodynamic instability risk mortality without swift intervention. An idea of when ectopic gestations are likely to present may be useful for logistic planning and facility readiness for case management. The study sought to assess the incidence of extrauterine gestation, mode of management and any link with seasonal and/or sociocultural events within the Cape Coast metropolis of Ghana over a 9-year review period.?Methods: A retrospective review of all cases of extrauterine pregnancies managed at the Cape Coast Teaching Hospital (CCTH) from January 2010 to December 2018 was conducted. Data on patient age, parity, month of presentation, site and laterality of ectopic gestation, number of abortions and deliveries were retrieved from hospital records and analysed. Yearly and monthly aggregated incidence of extrauterine pregnancies were computed.?Result: A total of 480 ectopic pregnancies out of 26,850 total pregnancies were seen over the period, giving an overall occurence of 17.9/1000 pregnancies and almost all were managed surgically. Half of all the cases occurred in the 20?-?29 years age group while the extremes of age recorded the lowest. An average of about 53 cases per year was recorded for the period under review. The peak months of occurrence were October and November. About 83% were ruptured with the ampulla region being the commonest site. Conclusion: The data suggests increased ectopic gestation occurrence in the Cape Coast metropolis about two months after the major traditional festivals and this may have implications for instituting mitigating measures, logistic management and facility preparedness for case management. 展开更多
关键词 Extrauterine PREGNANCY seasonality INCIDENCE Ghana MANAGEMENT Options
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Impact of seasonality on the prevalence and risk factors of Giardia lamblia infections among the aborigines
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作者 Samseh Abdullah Noradilah Norhayati Moktar +2 位作者 Ii Li Lee Fatmah Md Salleh Tengku Shahrul Anuar 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2019年第7期315-320,共6页
Objective: To determine the prevalence and risk factors of Giardia(G.) lamblia infections among the aboriginal community during the wet and dry seasons. Methods: A total of 473 stool samples from the aborigines in Tem... Objective: To determine the prevalence and risk factors of Giardia(G.) lamblia infections among the aboriginal community during the wet and dry seasons. Methods: A total of 473 stool samples from the aborigines in Temerloh, Pahang, Malaysia were collected during wet(n=256) and dry seasons(n=217). Smear of all the PVA-preserved stool samples were subjected to Trichrome staining and microscopic examination under 1 000 伊magnification(Nikon eclipse E100) for the detection of G. lamblia. Positivity was recorded based on the presence of G. lamblia in trophozoite and/or cyst forms. Results: The prevalence of giardiasis was 12.10% and 8.29% during the wet and dry season, respectively. Age of less or equal to 15 years old and presence of other family members with G. lamblia infection were found to be the significant risk factors to acquire G. lamblia infections during both seasons. Untreated water supply was the significant risk factor of giardiasis during the dry season. This study highlighted the possibility of anthroponotic transmission of G. lamblia during both seasons and waterborne transmission during the dry season in the aboriginal community. Conclusions: This study suggests that seasonal variation plays an important role in the prevalence and risk factor of G. lamblia infection in the aboriginal community. Therefore, close contact with Giardia-infected family members and water-related activities or usage of untreated water must be avoided to reduce the burden of G. lamblia infection in this community. 展开更多
关键词 GIARDIA seasonality ABORIGINE Anthroponotic WATERBORNE
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Birth seasonality and pattern in black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Mt. Lasha, Yunnan
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作者 Jin-Fa LI Yu-Chao HE +5 位作者 Zhi-Pang HUANG Shuang-Jin WANG Zuo-Fu XIANG Juan-Jun ZHAO Wen XIAO Liang-Wei CUI 《Zoological Research》 CAS CSCD 北大核心 2014年第6期474-484,共11页
Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primate... Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a "V" style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability. 展开更多
关键词 Rhinopithecus bieti Birth seasonality Birth pattern Birth synchrony
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Submesoscale motions and their seasonality in the northern Bay of Bengal
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作者 Lanman Li Xuhua Cheng +2 位作者 Zhiyou Jing Haijin Cao Tao Feng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第4期1-13,共13页
The unbalanced submesoscale motions and their seasonality in the northern Bay of Bengal(BoB)are investigated using outputs of the high resolution regional oceanic modeling system.Submesoscale motions in the forms of f... The unbalanced submesoscale motions and their seasonality in the northern Bay of Bengal(BoB)are investigated using outputs of the high resolution regional oceanic modeling system.Submesoscale motions in the forms of filaments and eddies are present in the upper mixed layer during the whole annual cycle.Submesoscale motions show an obvious seasonality,in which they are active during the winter and spring but weak during the summer and fall.Their seasonality is associated with the mixed layer instability that depends on the mixed layer depth(MLD).During the winter,the MLD provides a much greater reservoir of the available potential energy,which promotes mixed layer instability to develop active submesoscale motions.The variations of MLD are likely modulated by the larger scale motions and the influxes of freshwater.Further investigations imply that the MLD and the stratified barrier layer are combined to determine the vertical structure of the submesoscale motions.The shallow MLD and strong stratification below during the summer and fall seem to prevent the downward extension of submesoscale motions.But in spring when the weak stratification exists,the penetration depth exceeds the base of the barrier layer. 展开更多
关键词 submesoscale motions seasonality northern BoB mixed layer instability STRATIFICATION
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Influence of non-stationarity and auto-correlation of climatic records on spatio-temporal trend and seasonality analysis in a region with prevailing arid and semi-arid climate,Iran
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作者 Mahsa MIRDASHTVAN Mohsen MOHSENI SARAVI 《Journal of Arid Land》 SCIE CSCD 2020年第6期964-983,共20页
Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regi... Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regions.In this study,various climatic zones of Iran were investigated to assess the relationship between the trend and the stationarity of the climatic variables.The Mann-Kendall test was considered to identify the trend,while the trend free pre-whitening approach was applied for eliminating serial correlation from the time-series.Meanwhile,time series stationarity was tested by Dickey-Fuller and Kwiatkowski-Phillips-Schmidt-Shin tests.The results indicated an increasing trend for mean air temperature series at most of the stations over various climatic zones,however,after eliminating the serial correlation factor,this increasing trend changes to an insignificant decreasing trend at a 95%confidence level.The seasonal mean air temperature trend suggested a significant increase in the majority of the stations.The mean air temperature increased more in northwest towards central parts of Iran that mostly located in arid and semiarid climatic zones.Precipitation trend reveals an insignificant downward trend in most of the series over various climatic zones;furthermore,most of the stations follow a decreasing trend for seasonal precipitation.Furthermore,spatial patterns of trend and seasonality of precipitation and mean air temperature showed that the northwest parts of Iran and margin areas of the Caspian Sea are more vulnerable to the changing climate with respect to the precipitation shortfalls and warming.Stationarity analysis indicated that the stationarity of climatic series influences on their trend;so that,the series which have significant trends are not static.The findings of this investigation can help planners and policy-makers in various fields related to climatic issues,implementing better management and planning strategies to adapt to climate change and variability over Iran. 展开更多
关键词 climate change trend analysis stationarity tests serial correlation seasonality arid and semi-arid regions
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Changes in Seasonality in China under Enhanced Atmospheric CO_2 Concentration
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作者 XIA Jiang-Jiang YAN Zhong-Wei ZHOU Wen 《Atmospheric and Oceanic Science Letters》 2011年第1期12-17,共6页
Seasonality changes in China under elevated atmospheric CO2 concentrations were simulated using nine global climate models, assuming a 1% per year increase in atmospheric CO2. Simulations of 20th century experiments o... Seasonality changes in China under elevated atmospheric CO2 concentrations were simulated using nine global climate models, assuming a 1% per year increase in atmospheric CO2. Simulations of 20th century experiments of season changes in China from the periods 1961-80 to 1981-2000 were also assessed using the same models. The results show that the ensemble mean simula- tion of the nine models performs better than that of an individual model simulation. Compared the mean climatology of the last 20 years in the CO2-quadrupling experiments with that in the CO2-doubling ones, the ensemble mean results show that the hottest/coldest continuous-90-day (local summer/winter) mean temperature in- creased by 3.4/4.5℃, 2.7/2.9℃, and 2.9/4.1℃ in Northeast (NE), Southwest (SW), and Southeast (SE) China, respectively, indicating a weakening seasonal amplitude (SA), but by 4.4/4.0℃ in Northwest (NW) China, indicating an enlarging SA. The local summer lengthened by 37/30/66/54 days in NW, NE, SW, and SE China, respec- tively. In some models, the winter disappeared during the CO2-quadrupling period, judging by the threshold based on the CO2-doubling period. The average of the other model simulations show that the local winter shortened by 42/36/61/44 days respectively, in the previously mentioned regions. 展开更多
关键词 seasonality in China global warming SCENARIO CO2-increase experiment
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Soil Invertebrates in Different Land Use Systems: How Integrated Production Systems and Seasonality Affect Soil Mesofauna Communities
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作者 Mauricio Rumenos Guidetti Zagattol Cintia Carla Niva +5 位作者 Marcilio Jose Thomazini Dilmar Baretta Alessandra Santos Herlon Nadolny Guilherme Borges Xarao Cardoso George Gardner Brown 《Journal of Agricultural Science and Technology(B)》 2017年第3期158-169,共12页
The soil mesofauna plays a role in organic matter comminution and decomposition, and can be used as bioindicators, since they are sensitive to soil management, vegetation and climate changes. Hence, this study aimed t... The soil mesofauna plays a role in organic matter comminution and decomposition, and can be used as bioindicators, since they are sensitive to soil management, vegetation and climate changes. Hence, this study aimed to evaluate mesofauna density and diversity in different land use systems to identify faunal relationships with soil properties, management and seasonality. The study area included five land use systems in Ponta Grossa municipality, Parana State: integrated crop-livestock (ICL), integrated crop-livestock-forestry (ICLF), grazed native pasture (NP), Eucalyptus dunnii plantation (EU) and no-tillage (NT) cropping systems. In each system, eight soil samples for mesofauna were collected with Berlese funnels of 8 cm diameter along a transect in three replicate plots of 50 m × 100 m. For physical and chemical analysis, soil was sampled at five points per plot in two seasons: winter 2012 and autumn 2013. Data were statistically analyzed using ANOVA and Duncan's test (P 〈 0.05), nonparametric statistics (when necessary) and redundancy analysis (RDA). Diversity was calculated based on the group richness and Simpson index. The main mesofauna groups found were: Acarina, Collembola and Hymenoptera. Diplopoda, Enchytraeidae, Isopoda, Collembola, Hemiptera, Hymenoptera and Coleoptera larvae were more abundant in autumn than winter. Soil moisture was the main factor responsible for higher mesofauna abundance in autumn. Integrated production systems, especially ICLF had similar invertebrate community abundance and composition with EU, while NT favored Oribatid mites, although the use of insecticides, herbicides and fungicides reduced total mesofauna density. Most correlations between mesofauna and physical-chemical attributes in the winter were not observed in the autumn and vice versa, revealing that there are more factors involved in regulating soil mesofauna distribution. 展开更多
关键词 Soil invertebrates BIODIVERSITY soil management BIOINDICATORS seasonality moisture.
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An Assessment of the Within-Year Seasonality in the Loan Loss Provisioning Behavior of European Banks
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作者 Enrico Laghi Michele Di Marcantonio Maria Teresa Bianchi 《Journal of Modern Accounting and Auditing》 2014年第12期1167-1186,共20页
This study aims at assessing whether a significant within-year seasonality exists in the loan loss provisioning behavior of European listed banks observed in the period from 2004 to 2013. Since the accuracy of auditin... This study aims at assessing whether a significant within-year seasonality exists in the loan loss provisioning behavior of European listed banks observed in the period from 2004 to 2013. Since the accuracy of auditing processes and the level of disclosure requirements in financial reports differ among quarters, during the year, banks may have a leeway to underestimate and postpone the complete provisioning of loan losses in the less regulated and less audited quarters. We hypothesize that those differences are relevant factors which determine non-lower or significantly higher average levels of loan loss provisions in the half-yearly and especially in the annual financial reports than in the interim management statements disclosed in the first and the third quarters of the year. We also investigate the impact of the recent financial crisis and develop a special analysis for the ltalian banks' case. The empirical results support our hypotheses, suggesting that, in some cases, a convergence among quarterly levels of auditing processes and disclosure requirements may be needed. Our work contributes to the existing literature by providing additional evidences and considerations on the within-year seasonality in the loan loss provisioning behavior of European listed banks observed in the last decade. 展开更多
关键词 loan loss provisions seasonality BANKS earnings management means comparison
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Monthly Seasonality in the Top 50 Australian Stocks
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作者 Liu Benjamin Li Bin 《Journal of Modern Accounting and Auditing》 2011年第4期380-390,共11页
We studied monthly seasonality in the top 50 Australian stocks across different industry sectors. Unlike other Australian studies, we examined monthly seasonality using stock return data of individual companies for th... We studied monthly seasonality in the top 50 Australian stocks across different industry sectors. Unlike other Australian studies, we examined monthly seasonality using stock return data of individual companies for the period of January 1980 through to August 2010. We found that stock returns of over half of the 50 companies are significantly positive in April and December, and most companies have low stock returns in October. Seven companies have higher returns in April than in other months of the year, most of which are banking and financial services companies, while six companies have lower returns in February than in other months. Although Australia has a July-June taxation cycle, we found that only three stocks have a July anomaly. The findings are inconsistent with the tax-loss selling hypothesis and other studies on the Australian equity markets (e.g., Brown, Keim, Kleidon, & Marsh, 1983; Brailsford & Easton, 1991). However, our findings are generally consistent with Bonin and Moses (1974) on individual stock seasonality 展开更多
关键词 Australian stock market market efficiency market anomaly monthly effect January effect seasonality
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Seasonality of ER Admissions in Northwestern Pennsylvania: A Cross-Sectional Study
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作者 Thais Rafael Guimaraes Rebecca Smullin Dawson 《Open Journal of Emergency Medicine》 2016年第2期45-52,共9页
Seasonality, in the context of emergency room (ER) admissions, can be described as the periodic incidence of disease, corresponding to seasons, or other pre-established calendar periods. Respiratory diseases, in gener... Seasonality, in the context of emergency room (ER) admissions, can be described as the periodic incidence of disease, corresponding to seasons, or other pre-established calendar periods. Respiratory diseases, in general, show a seasonal pattern with incidence peak at the winter season, however research still presents a considerable amount of inconsistency. Incidence of cardiovascular diseases (CVD) is also very well linked to the cold season. Gastrointestinal, genitourinary and neurological diseases are poorly studied in regards their seasonal patterns. This study aimed to assess seasonality of the five categories of diseases–respiratory, cardiovascular, gastrointestinal, genitourinary, and neurological-using data from a community hospital in northwestern PA. We analyzed 14 years (2000-2014) of data from the Meadville Medical Center (MMC) ER admissions. For each ER admission case, we had information about ICD-9 code, sex, insurance, race, age and date, time and year of admission. Statistical analyses were performed using SAS 9.4 University version software. We found significantly fewer cases of respiratory diseases in spring (OR = 0.757), summer (OR = 0.579), and fall (OR = 0.741), when comparing to the winter season;however, seasonal differences were not found for cardiovascular, genitourinary, and neurological diseases. The implications of these results will primarily be used to improve Meadville’s public health policies for cold seasons, and more specifically, implement programs that prepare the ER to receive and treat respiratory cases more efficiently in the cold season. 展开更多
关键词 seasonality Emergency Room Meadville Respiratory Diseases WINTER
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