LOCAL AND REGIONAL RESISTANCE TO FENVALERATE IN PSYLLA PYRICOLA FOERSTER (HOMOPTERA: PSYLLIDAE) IN WESTERN NORTH AMERICA

1989 ◽  
Vol 121 (2) ◽  
pp. 121-129 ◽  
Author(s):  
B.A. Croft ◽  
E.C. Burts ◽  
H.E. van de Baan ◽  
P.H. Westigard ◽  
H. Riedl

AbstractFenvalerate resistance was monitored in Psylla pyricola Foerster populations at 51 sites in Washington, Oregon, California, and British Columbia during early 1988. Resistance levels ranged from susceptible in an organic orchard in the Willamette Valley, OR, and at several other sites in Oregon and California, to highly resistant (> 100-fold compared with a susceptible strain) at several sites in central Washington. Generally, resistance levels were greater in the north than the south. In the Wenatchee and Yakima/Ellensburg, WA, areas, pyrethroid resistance was areawide, showing similar levels in both heavily treated and untreated orchards. In the Willamette Valley, OR, pyrethroid resistance was local and more consistent with the treatment histories of individual orchards. Factors influencing regional resistance appeared to be the species pool size of resistant and susceptible pear psylla, the intensity of spraying, and the unique host plant, life cycle, and dispersal attributes of this pest. Reasons for high regional resistance in central Washington and not in southerly areas are unknown, but this pattern is consistent with earlier patterns of insecticide resistance in pear psylla. The observed trends in fenvalerate resistance are discussed in relation to limiting resistance in pear psylla.

Author(s):  
Mingjian Zhou ◽  
Heng Zhou ◽  
Jie Shen ◽  
Zhirong Zhang ◽  
Cecilia Gotor ◽  
...  

2012 ◽  
Vol 84 (8) ◽  
pp. 1226-1226
Author(s):  
J. S. Kussi ◽  
H. Richert ◽  
U. P. Stramma ◽  
M. Rittmeister ◽  
S. Zeck

2021 ◽  
Author(s):  
Agnieszka Zienkiewicz ◽  
Marta Saldat ◽  
Krzysztof Zienkiewicz

In plants, lipids serve as one of the major and vital cellular constituents. Neutral lipids reserves play an essential role in the plant life cycle by providing carbon and energy equivalents for periods of active metabolism. The most common form of lipid storage are triacylglycerols (TAGs) packed into specialized organelles called lipid droplets (LDs). They have been observed in diverse plant organs and tissues, like oil seeds or pollen grains. LDs consist of a core, composed mostly of TAGs, enclosed by a single layer of phospholipids that is decorated by a unique set of structural proteins. Moreover, the recent advances in exploration of LDs proteome revealed a plethora of diverse proteins interacting with LDs. This is likely the result of a highly dynamic nature of these organelles and their involvement in many diverse aspect of cellular metabolism, tightly synchronized with plant developmental programs and directly related to plant-environment interactions. In this review we summarize and discuss the current progress in understanding the role of LDs and their cargo during plants life cycle, with a special emphasis on developmental aspects.


2021 ◽  
Vol 2 (2) ◽  
pp. 395-412
Author(s):  
Patrick Martineau ◽  
Hisashi Nakamura ◽  
Yu Kosaka

Abstract. The wintertime influence of tropical Pacific sea surface temperature (SST) variability on subseasonal variability is revisited by identifying the dominant mode of covariability between 10–60 d band-pass-filtered surface air temperature (SAT) variability over the North American continent and winter-mean SST over the tropical Pacific. We find that the El Niño–Southern Oscillation (ENSO) explains a dominant fraction of the year-to-year changes in subseasonal SAT variability that are covarying with SST and thus likely more predictable. In agreement with previous studies, we find a tendency for La Niña conditions to enhance the subseasonal SAT variability over western North America. This modulation of subseasonal variability is achieved through interactions between subseasonal eddies and La Niña-related changes in the winter-mean circulation. Specifically, eastward-propagating quasi-stationary eddies over the North Pacific are more efficient in extracting energy from the mean flow through the baroclinic conversion during La Niña. Structural changes of these eddies are crucial to enhance the efficiency of the energy conversion via amplified downgradient heat fluxes that energize subseasonal eddy thermal anomalies. The enhanced likelihood of cold extremes over western North America is associated with both an increased subseasonal SAT variability and the cold winter-mean response to La Niña.


1964 ◽  
Vol 21 (5) ◽  
pp. 933-939 ◽  
Author(s):  
Richard H. Rosenblatt

A new species, Pholis clemensi, referred to the family Pholidae, is named and described from 12 specimens taken in southern British Columbia waters and the Strait of Juan de Fuca. Pholis clemensi is compared with other members of the genus, and a key is given to the North American species.


2020 ◽  
Vol 33 (6) ◽  
pp. 2427-2447 ◽  
Author(s):  
Nathaniel C. Johnson ◽  
Lakshmi Krishnamurthy ◽  
Andrew T. Wittenberg ◽  
Baoqiang Xiang ◽  
Gabriel A. Vecchi ◽  
...  

AbstractPositive precipitation biases over western North America have remained a pervasive problem in the current generation of coupled global climate models. These biases are substantially reduced, however, in a version of the Geophysical Fluid Dynamics Laboratory Forecast-Oriented Low Ocean Resolution (FLOR) coupled climate model with systematic sea surface temperature (SST) biases artificially corrected through flux adjustment. This study examines how the SST biases in the Atlantic and Pacific Oceans contribute to the North American precipitation biases. Experiments with the FLOR model in which SST biases are removed in the Atlantic and Pacific are carried out to determine the contribution of SST errors in each basin to precipitation statistics over North America. Tropical and North Pacific SST biases have a strong impact on northern North American precipitation, while tropical Atlantic SST biases have a dominant impact on precipitation biases in southern North America, including the western United States. Most notably, negative SST biases in the tropical Atlantic in boreal winter induce an anomalously strong Aleutian low and a southward bias in the North Pacific storm track. In boreal summer, the negative SST biases induce a strengthened North Atlantic subtropical high and Great Plains low-level jet. Each of these impacts contributes to positive annual mean precipitation biases over western North America. Both North Pacific and North Atlantic SST biases induce SST biases in remote basins through dynamical pathways, so a complete attribution of the effects of SST biases on precipitation must account for both the local and remote impacts.


Author(s):  
Ki-Sig Kang ◽  
Claude Russell Clark ◽  
Poong Eil Juhn

For the past couple of decades there has been a change of emphasis in the world nuclear power from that of building new Nuclear Power Plants (NPP) to that of taking measures to optimize the life cycle of operational plants. National approaches in many countries showed an increase of interest in Plant Life Management (PLIM), both in terms of plant service life assurance and in optimizing the service or operational life of NPP. A strong convergence of views is emerging from different National approaches, particularly in the area of the economic aspects of NPP operation and in the evolution in the scope of NPP PLIM. The latter can directly affect the cost of electricity from NPP in an increasingly competitive environment. The safety considerations of a NPP are paramount and those requirements have to be met to obtain and to extend/renew the operating license. To achieve the goal of the long term safe, economic and reliable operation of the plant an Integrated Life Cycle Management Programme (ILCMP) is necessary. Some countries already have advanced PLIM Programmes while others still have none. The ILCMP objective is to identify all that factors and requirements for the overall plant life cycle. The optimization of these requirements would allow for the minimum period of the investment return and maximum of the revenue from the sell of the produced electricity. Recognizing the importance of this issue and in response to the requests of the Member States the IAEA Division of Nuclear Power implements the Sub-programme on “Engineering and Management Support for Competitive Nuclear Power”. Four projects within this sub-programme deal with different aspects of the NPP life cycle management with the aim to increase the capabilities of interested Member States in implementing and maintenance of the competitive and sustainable nuclear power. Although all four projects contain certain issues of PLIM there is one specific project on guidance on engineering and management practices for optimization of NPP service life including decommissioning. This particular project deals with different specific issues of NPP life management including aspects of ageing phenomena and their monitoring, issues of control and instrumentation, maintenance and operation issues, economic evaluation of NPP life cycle management including guidance on its earlier shut down and decommissioning. The paper describes in detail the full scope IAEA activities on different issues of NPP life management and some of its achievements in this field during the nearest past as well as plans for the future.


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