Population dynamics ofMyzus persicaeon tobacco in Yunnan Province, China, before and after augmentative releases ofAphidius gifuensis

2009 ◽  
Vol 19 (2) ◽  
pp. 219-228 ◽  
Author(s):  
S. Yang ◽  
S.Y. Yang ◽  
C.P. Zhang ◽  
J.-N. Wei ◽  
R.P. Kuang
Keyword(s):  
Population Dynamics ◽  
Yunnan Province ◽  
Before And After ◽  
Augmentative Releases

scholarly journals Population dynamics of a commercially harvested, non-native bivalve in an area protected for shorebirds: Ruditapes philippinarum in Poole Harbour, UK

2019 ◽  
Vol 32 ◽  
pp. 10 ◽  
Author(s):  
Leo John Clarke ◽  
Luciana S. Esteves ◽  
Richard A. Stillman ◽  
Roger J.H. Herbert
Keyword(s):  
Population Dynamics ◽  
Marine Protected Area ◽  
Condition Index ◽  
Ruditapes Philippinarum ◽  
Ecological Interactions ◽  
Fishing Season ◽  
Before And After ◽  
Harvesting Efficiency ◽  
The Uk ◽  
Lower Biomass

The Manila clam Ruditapes philippinarum is one of the most commercially valuable bivalve species worldwide and its range is expanding, facilitated by aquaculture and fishing activities. In existing and new systems, the species may become commercially and ecologically important, supporting both local fishing activities and populations of shorebird predators of conservation importance. This study assessed potential fishing effects and population dynamics of R. philippinarum in Poole Harbour, a marine protected area on the south coast of the UK, where the species is important for oystercatcher Haematopus ostralegus as well as local fishers. Sampling was undertaken across three sites of different fishing intensities before and after the 2015 fishing season, which extends into the key overwintering period for shorebird populations. Significant differences in density, size and condition index are evident between sites, with the heavily dredged site supporting clams of poorer condition. Across the dredge season, clam densities in the heavily fished area were significantly reduced, with a harvesting efficiency of legally harvestable clams of up to 95% in this area. Despite occurring at significantly higher densities and growing faster under heavy fishing pressure, lower biomass and condition index of R. philippinarum in this area, coupled with the dramatic reduction in densities across the fishing season, may be of concern to managers who must consider the wider ecological interactions of harvesting with the interest of nature conservation and site integrity.

scholarly journals Antagonism and population dynamics of Acinetobacter baumannii from US military treatment centers

2017 ◽  
Author(s):  
Rae A Heitkamp ◽  
Amy M Zale ◽  
Benjamin C Kirkup
Keyword(s):  
Population Dynamics ◽  
Acinetobacter Baumannii ◽  
Bacterial Species ◽  
Hospital Setting ◽  
Antagonistic Activity ◽  
Resistant Bacteria ◽  
Natural Environments ◽  
Bacterial Populations ◽  
Starting Point ◽  
Before And After

Antibiotic-resistant bacteria complicate many infections and can be difficult to eradicate from hospitals. The population dynamics and ecology of these organisms in the hospital setting, however, is not well understood. Here, we report extensive strain-based antagonistic interactions occurring in military clinical isolates of Acinetobacter baumannii, a bacterial species that causes many drug-resistant hospital-associated infections. Sequence-based phylogenetic analysis of isolates allowed for differentiation to two major clades, with one of the clades representing two closely related genetic groups. Antagonistic activity was detected using a spot-plate assay to test pairwise interactions of all isolates. Isolates exhibited extensive and diverse patterns of antagonism against other isolates. One major clade of isolates had a distinct change in antagonism phenotype between isolates that differed by one base pair out of ~1500bp sequenced, with consistent antagonism of one group of isolates by the other. Both the antagonistic and the sensitive group exhibited extensive drug resistance. The first isolate of the antagonistic group was cultured in May 2010. The proportion of isolates from the antagonistic group collected before and after July 2010 increased from 2% to 76%. The results of this early study of the ecology of hospital-associated bacterial populations are discussed in the context of the species ecology of bacteria in natural environments. This work is a potential starting point for investigations into ecological interventions for infection control in hospitals.

scholarly journals Weed population dynamics in rice crops resulting from post-emergent herbicide applications

2017 ◽  
Vol 70 (1) ◽  
pp. 8035-8043
Author(s):  
Javier Ramírez ◽  
Verónica Hoyos ◽  
Guido Plaza
Keyword(s):  
Population Dynamics ◽  
Community Structure ◽  
Relative Frequency ◽  
Importance Value Index ◽  
Importance Value ◽  
Weed Population ◽  
Weed Communities ◽  
Weed Population Dynamics ◽  
Importance Index ◽  
Before And After

Studies on weed population dynamics are based on observing and recording changes in weed communities in response to effects of disturbances in crop management. The present study aimed to evaluate weed population dynamics in rice crops in Tolima, Colombia, resulting from post-emergent herbicide applications. Sampling was carried out in 0.1% of the cultivated area, marking out a 1 ha area in each commercial lot. Samples were taken before and after post-emergent applications. Evaluated variables were frequency, density, and cover. The data were analyzed using the Importance Value Index (IVI). Results demonstrated that Echinochloa colona was the most important weed of all of the evaluated zones, before and after post-emergent herbicide applications. Other notable species included Digitaria ciliaris, Cyperus iria and Ischaemum rugosum. Relative frequency variable was the most influential on the importance index of the species. Furthermore, herbicide applications generated changes in the community structure in the evaluated zones and in each evaluation.

Population dynamics of tree seedlings in a mixed dipterocarp rainforest before and after logging and crown liberation

1996 ◽  
Vol 81 (1-3) ◽  
pp. 85-94 ◽  
Author(s):  
Jussi Kuusipalo ◽  
Yusuf Jafarsidik ◽  
Göran Ådjers ◽  
Kari Tuomela
Keyword(s):  
Population Dynamics ◽  
Tree Seedlings ◽  
Before And After

scholarly journals Epidemiological characteristics of hand, foot, and mouth disease in Yunnan Province, China, 2008–2019

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Li Jiang ◽  
Hongchao Jiang ◽  
Xin Tian ◽  
Xueshan Xia ◽  
Tian Huang
Keyword(s):  
Vaccination Coverage ◽  
Yunnan Province ◽  
Enterovirus 71 ◽  
Case Fatality ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Vaccination Coverage Rate ◽  
Foot And Mouth ◽  
Before And After ◽  
Epidemiological Characteristics

Abstract Background Since 2016, enterovirus 71 (EV71) vaccines have been approved for market entry, and little is known about how the epidemiology of hand, foot, and mouth disease (HFMD) has been affected by the introduction of the vaccines in Yunnan Province. The study describes the epidemiological characteristics of HFMD before and after the introduction of EV71 vaccination in Yunnan Province. Methods Surveillance data collected between 2008 and 2019 were analyzed to produce epidemiological distribution on cases, etiologic composition, and EV71 vaccination coverage, as well as to compare these characteristics before and after EV71 vaccination. Results A total of 1,653,533 children received EV71 vaccines from 2016 through 2019 in Yunnan. The annual EV71 vaccination coverage rate ranged from 5.53 to 15.01% among children ≤5 years old. After the introduction of EV71 vaccines, the overall incidence of HFMD increased and reached over 200 cases per 100,000 population-years in 2018 and 2019. However, the case severity and case fatality rate decreased and remained lower than 1 and 0.005% after 2016, respectively. EV71-associated mild, severe and fatal cases sharply decreased. The predominant viral serotype changed to non-EV71/non-CV-A16 enteroviruses which were detected across the whole province. Conclusions Non-EV71/non-CV-A16 enteroviruses became the predominant strain and led to a higher incidence in Yunnan. Expanding EV71 vaccination and strengthening laboratory-based surveillance could further decrease the burden of severe HFMD and detect and monitor emerging enteroviruses.

scholarly journals Population dynamics and diversity of butterflies in Ailaoshan and Wuliangshan national nature reserves, Yunnan Province

2020 ◽  
Vol 28 (8) ◽  
pp. 921-930
Author(s):  
Qun Wang ◽  
Zhixiang Guo ◽  
Jinbin Li ◽  
Kaibo Wang ◽  
Wenwei Wu ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Yunnan Province ◽  
Nature Reserves ◽  
National Nature Reserves

A validated population-dynamics model for Scrobicularia plana (Mollusca, Bivalvia) in a south-western European estuary

2009 ◽  
Vol 60 (5) ◽  
pp. 404 ◽  
Author(s):  
P. M. Anastácio ◽  
T. Verdelhos ◽  
J. C. Marques ◽  
M. A. Pardal
Keyword(s):  
Population Dynamics ◽  
Extreme Values ◽  
River Estuary ◽  
Model Performance ◽  
Dynamics Model ◽  
The North ◽  
Population Dynamics Model ◽  
Scrobicularia Plana ◽  
Before And After ◽  
System Restoration

During a recent intervention in the Mondego River estuary, Portugal, the existing connection between the north and the more eutrophic south arm was enlarged, a nutrient-enriched freshwater input was diverted to the north arm and the remaining seagrass patches were protected from human activity. System restoration did not involve disruption of the sediment and successfully reduced the eutrophic state of the estuary. This provided an excellent opportunity to test a population-dynamics model of a common European estuarine bivalve, Scrobicularia plana, (da Costa, 1778) before and after the intervention. The model simulated the number of individuals in three different sampling stations, before and after system restoration, and is regulated by water temperature, salinity and population density. Our analysis indicated that the occurrence of extreme values of the environmental variables has the strongest effect on the model response and possibly on the real system. The model was calibrated and validated with independent data sets and the model performance was highest under the conditions after the management. This corroborates the notion that system restoration was successful and indicates that the system became more predictable after management.

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