scholarly journals Effect of pirimicarb application on field ppulations of Myzus persicae (Sulz.) (Homoptera: Aphididae) with different esterase levels

2000 ◽  
Vol 29 (4) ◽  
pp. 739-747
Author(s):  
Rui S. Furiatti ◽  
Sonia M. N. Lázzari

The frequency and intensity of Myzus persicae (Sulz.) resistance were studied using bioassays and biochemical tests in two potato crops in Ibicoara, Bahia. Both areas received several insecticide applications which failed to control M. persicae. By the end of the crop season, one of the areas received two applications of pirimicarb and the other was not sprayed. Six samples of 700 aphids each were randomly collected before and after the pirimicarb applications, with an interval of four days. Specimens of M. persicae were also collected from isolated potato plants. At the laboratory, the samples were characterized by the CL50 based on insecticide bioassays and by total esterase activity using colorimetric assays. After the pirimicarb applications, the susceptible (S), the moderate resistant (R1) and mixed S/R1populations presented decreasing resistance frequencies (from 36.6 to 9.9; 12,0 to 7.5 and 11.4 to 5.9%, respectively). On the other hand, high resistant individuals (R2), extremely resistant (R3), and mixed populations of R1/R2 had increasing frequencies (from 17.7 to 36.7%; 2.3 to 9.1%, and 20.0 to 30.8%, respectively). The survival of S individuals was probably due to their wandering behavior on the plants to avoid sprayed areas. All changes in frequency were reflected in the LC50 and in the resistance ratio (rr). In the pirimicarb untreated area, high frequencies of R2, R3 and R1/R2 were observed. High frequency and resistance intensity of M. persicae in areas under intensive insecticide applications can be related to the selection of resistant populations and due to the entrance of winged migrants from spontaneous plants, where the frequency of R2+R3 was 81.4%.

2021 ◽  
Author(s):  
Jathurshan Pradeepkumar ◽  
Mithunjha Anandakumar ◽  
Vinith Kugathasan ◽  
Andrew Seeber ◽  
Dushan N Wadduwage

A key challenge in optical microscopy is to image fast at high-resolution. To address this problem, we propose "Physics Augmented U-Net", which combines deep learning and structured illumination microscopy (SIM). In SIM, the structured illumination aliases out-of-band high-frequencies to the passband of the microscope; thus SIM captures some high-frequencies even when the image is sampled at low-resolution. To utilize these features, we propose a three-element method: 1) a modified U-Net model, 2) a physics-based forward model of SIM 3) an inference algorithm combining the two models. The modified U-Net architecture is similar to the seminal work, but the bottleneck is modified by concatenating two latent vectors, one encoding low-frequencies (LFLV), and the other encoding high-frequencies (HFLV). LFLV is learned by U-Net contracting path, and HFLV is learned by a second encoding path. In the inference mode, the high-frequency encoder is removed; HFLV is then optimized to fit the measured microscopy images to the output of the forward model for the generated image by the U-Net. We validated our method on two different datasets under different experimental conditions. Since a latent vector is optimized instead of a 2D image, the inference mode is less computationally complex. The proposed model is also more stable compared to other generative prior-based methods. Finally, as the forward model is independent of the U-Net, Physics Augmented U-Net can enhance resolution on any variation of SIM without further retraining.


1997 ◽  
Vol 07 (02) ◽  
pp. 291-311 ◽  
Author(s):  
Miguel Lobo ◽  
Eugenia Pérez

The stiff problem here considered models the vibrations of a body consisting of two materials, one of them very stiff with respect to the other. We study the asymptotic behavior of the eigenvalues and eigenfunctions of the corresponding spectral problem, when the stiffness constant of only one of the materials tends to 0. We show that the associated operator has a discrete spectrum "converging", in a certain sense, towards a continuous spectrum in [0,∞) corresponding to an operator. We also provide information on the structure of the eigenfunctions associated with the high frequencies.


2021 ◽  
Author(s):  
Anne Maass

In this paper, we argue that some fundamental concepts and tools of signal processing may beeffectively applied to represent and interpret social cognition processes. From this viewpoint,individuals or, more generally, social stimuli are thought of as a weighted sum of harmonics withdifferent frequencies: Low frequencies represent general categories such as gender, ethnic group,nationality, etc., whereas high frequencies account for personal characteristics. Individuals arethen seen by observers as the output of a filter that emphasizes a certain range of high or lowfrequencies. The selection of the filter depends on the social distance between the observingindividual or group and the person being observed as well as on motivation, cognitive resourcesand cultural background. Enhancing low- or high-frequency harmonics is not on equal footing, thelatter requiring supplementary energy. This mirrors a well-known property of signal processingfilters. More generally, in the light of this correspondence, we show that several established resultsof social cognition admit a natural interpretation and integration in the signal processinglanguage. While the potential of this connection between an area of social psychology and one ofinformation engineering appears considerable (compression, information retrieval, filtering,feedback, feedforward, sampling, aliasing, etc.), in this paper we shall limit ourselves to layingdown what we consider the pillars of this bridge on which future research may be founded.


2017 ◽  
Vol 26 (3S) ◽  
pp. 430-435 ◽  
Author(s):  
Arthur Boothroyd ◽  
Carol Mackersie

Purpose The purpose of the current study was to evaluate user reactions to custom software designed for self-adjustment of amplification. Method “Goldilocks” software was developed to allow user exploration and selection of preferred levels of overall output, low-frequency cut, and high-frequency boost while listening to preprocessed speech. Thirteen hearing-aid users and 13 nonusers self-adjusted before and after taking a speech perception test incorporated into the software. Results All 26 participants were able to complete the 2 adjustments and the intervening test in an average of 6.5 min—20 of them from on-screen instructions without experimenter help. Relative to a generic starting condition, the average participant opted to increase overall output, reduce low-frequency cut, and increase high-frequency boost. The first and second self-selected values were highly correlated, but there was evidence of further increases of overall volume and high-frequency boost after speech perception testing with the initial adjustment. There was no evidence that prior hearing-aid experience affected the ability to understand or complete the self-fitting process. Conclusions This approach to hearing-aid self-fitting can be a speedy, reliable, and feasible alternative to, or supplement to, conventional fitting procedures, but many questions remain to be answered.


1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.


2020 ◽  
Vol 1 (12) ◽  
pp. 40-42
Author(s):  
F. Yu. Daurova ◽  
D. I. Tomaeva ◽  
S. V. Podkopaeva ◽  
Yu. A. Taptun

Relevance: the reason for the development of complications in endodontic treatment is poor-quality instrumental treatment root canals.Aims: a study of the animicrobial action and clinical efficacy of high-frequency monopolar diathermocoagulation in the treatment of chronic forms of pulpitis.Materials and methods: 102 patients with various chronic forms of pulpitis were divided into three groups of 34 patients each. In the first two groups, high-frequency monopolar diathermocoagulation was used in endodontic treatment in different modes. In the third group, endodontic treatment was carried out without the use of diathermocoagulation (comparison group). The root canal microflora in chronic pulpitis in vivo was studied twice-before and after diathermocoagulation.Results: it was established that high-frequency monopolar diathermocoagulation in the effect mode is 3, power is 4 (4.1 W) and effect is 4, power is 4 (5.4 W) with an exposure time of 3 seconds, it has a pronounced antibacterial effect on all presented pathogenic microflora obtained from the root canals of the teeth.


Author(s):  
Zimmatul Liviana

The research grammatical interference in a collection ofshort stories Biarkan Aku Memula iwork Nurul F. Hudaisa collection ofshort storiesset in the back that Is start work Let Nurul F. Huda contains many grammatical interference.The problem of this   study were(1)how   the various morphologi calinterference containedin   a   collection of short stories Biarkan Aku Memulai work Nurul F. Huda. (2)how the various syntactic interference contained in a collection of short stories Biarkan Aku Memulai work Nurul F. Huda. The purposeof this studyis to describe the morphological and         Syntactic interference contained in a collection of short stories Biarkan Aku Memulai work Nurul F. Huda. Sociolinguistics is the study of language variation and use in society. Interference is the event of the use of language elements of one into the other language elements that occur in the speakers themselves. This research uses descriptive qualitative method because to describe the actual realityin order to obtainan accurateand objective. Qualitative descriptive methods were used to analyzethe elements ofa word orphrase that incorporated elements of other languages with the analysis and description of the formulation of the problem is the answer. Data collection techniques using observation techniques, the determination ofthe object of research, the selection of short stories.Based on the analysis of the data in this study can be found that there are six forms of interference morphology, namely (1) the prefix nasal N-sound, (2) the addition of the suffix, (3) the exchange prefix, (4) exchange suffixes, (5) exchange konfiks, (6) removal affixes. While the syntactic interference only on the words and phrases in a sentence. The results of the study it can be concluded that the interference morphology more common than syntactic interference.


2018 ◽  
Vol 17 (6) ◽  
pp. 159-166
Author(s):  
Halina Kurzawińska ◽  
Stanisław Mazur ◽  
Małgorzata Nadziakiewicz ◽  
Jacek Nawrocki

The aim of this study was to determine whether the weeds accompanying potato crops can be a source of Alternaria spp. causing Alternaria leaf blight and to determine the genetic similarities of Alternaria alternata isolates infecting selected weeds: Chenopodium album, Cirsium arvense and tested potato cultivar. Three-year field experiment was conducted on the potato cultivar ‘Vineta N’. The isolates were classified into different species on the basis of macro- and microscopic features. In each year of the study, A. alternata dominated among the isolated fungi colonizing the leaves of potato plants and the selected weeds. The genetic similarities of A. alternata isolates was determined by the RAPD-PCR method. Tested genetic forms of A. alternata were closely related; only small differences in the pattern of the separated amplification products was evidenced. The dominance of A. alternata on the weeds accompanying potato crops suggests that if weed infestation is extensive, the pathogen is very likely to spread and its population to increase.


2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.


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