scholarly journals Exceeding the threshold value for Trioza apicalis Förster 1848 in carrot fields did not cause damage as revealed during monitoring in Germany from 2017–2020

2021 ◽  
Author(s):  
J. Sauer ◽  
A. Dewert ◽  
P. Hondelmann ◽  
R. Meyhöfer ◽  
M. Hommes ◽  
...  
Keyword(s):  
Threshold Value ◽  
Threshold Level ◽  
Total Loss ◽  
Sticky Traps ◽  
Study Region ◽  
Action Threshold ◽  
Close Proximity ◽  
Chemical Pesticides

AbstractThe carrot psyllid Trioza apicalis Förster 1848 is a carrot pest in Europe that can cause serious damages in case of massive occurrence. Damages up to a total loss of yield have been reported from Scandinavian countries but also from Switzerland. The action threshold to control the pest with chemical pesticides is 0.2 T. apicalis per day and trap caught by sticky traps. We investigated the number of T. apicalis with sticky traps on carrot fields of the study regions Lüneburg/Uelzen and Hameln/Bad Pyrmont in Germany, during the period 2017–2020. The number of T. apicalis caught was generally very low in both study regions. On several fields in successive weeks almost no individuals were found in the study region Hameln/Bad Pyrmont. In Lüneburg/Uelzen was at least one field each year where the number of carrot psyllid was clearly higher than in all other fields and exceeded the threshold level. Surprisingly on carrot fields in close proximity to carrot fields from the previous year, the T. apicalis numbers were only slightly increased. Nonetheless, no loss of yield was reported for any of the fields in the four years of the study, although the generally defined threshold has been exceeded on many of the investigated carrot fields.

Home Automation by Brain-Computer Interface

2014 ◽  
pp. 502-510
Author(s):  
Eduardo G. Nieva ◽  
María F. Peralta ◽  
Diego A. Beltramone
Keyword(s):  
Frontal Lobe ◽  
Brain Computer Interface ◽  
Heating System ◽  
Threshold Value ◽  
Threshold Level ◽  
Computer Interface ◽  
Second Step ◽  
Electroencephalographic Signals ◽  
Commercial Device ◽  
The Brain

In the present work, the authors use the Brain Computer Interface technology to allow the dependent persons the utilization of the basic elements of their house, such as turning on and turning off lamps, rolling up and down a roller shutter, or switching on the heating system. For doing this, it is necessary to automate these devices and to centralize its managing in a platform, which constitutes a domotics system. In order to achieve this, the authors have used the MindWave NeuroSky ® commercial device. It is affordable, portable, and wireless, and senses and delivers the computer the electroencephalographic signals produced in the frontal lobe and the levels of attention, relaxation, and blinking to the computer. In order to determine the efficiency of the obtained signals a test software was designed, which verified the operation´s device with different persons. The authors conclude that the easiest way to control the attention levels is concentrating on a certain point, and the way to control the relaxation levels is by closing the eyes. As a second step, the authors develop a software that takes the signal from the EEG (Electro Encephalo Graphy) sensor, processes it, and sends signals via USB to an Arduino board, which is associated with electronics that complies the different tasks. The user chooses the action by managing the attention levels. When they are higher than a particular threshold value, the action is executed. In order to disable this action, the user must lower the threshold level and overcome it again. This is the simplest and fastest way to handle, but it brings several problems: if the user concentrates for any other reason and this signal exceeds the threshold, it causes the activation of an involuntary action. To solve this problem, the authors use a three variables combination that can become independent of each other thru training properly. These variables are attention, meditation, and blink. When you comply with the three simultaneous previously established conditions, the action is executed, and when they return to fulfill the conditions, the action is deactivated. The software also has the feature of personalizing its conditions, so it can be best for any user, even a novice one.

scholarly journals Evaluation of Pesticide Residue Dynamics in Lettuce, Onion, Leek, Carrot and Parsley

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 680
Author(s):  
Tereza Horská ◽  
František Kocourek ◽  
Jitka Stará ◽  
Kamil Holý ◽  
Petr Mráz ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Threshold Value ◽  
Vegetable Production ◽  
Order Kinetic ◽  
Pesticide Application ◽  
Time Of Application ◽  
Iceberg Lettuce ◽  
Action Threshold ◽  
Pesticide Formulations ◽  
Crop Harvest

The dynamics of 32 active substances contained in pesticide formulations (15 fungicides and 17 insecticides) were analyzed in iceberg lettuce, onion, leek, carrot, and parsley. Pesticide residues were monitored from the time of application until harvest. In total, 114 mathematical models of residue dissipation were developed using a first-order kinetic equation. Based on these models, it was possible to predict the action pre-harvest interval (the time between the last pesticide application and crop harvest) needed to attain a targeted action threshold (value significantly lower than the maximum limit) for low-residue vegetable production. In addition, it was possible to determine an action pre-harvest interval based on an action threshold of 0.01 mg kg−1 to produce vegetables intended for zero-residue production. The highest amount of pesticide residues were found in carrot and parsley leaves several days after treatment, and pesticide dissipation was generally slow. Lower amounts were found in leeks and lettuce, but pesticide dissipation was faster in lettuce. According to our findings, it seems feasible to apply reduced pesticide amounts to stay below unwanted residue levels. However, understanding the effectivity of reduced pesticide application for controlling relevant pest organisms requires further research.

scholarly journals AMBANG KENDALI PENGGEREK BUAH KAPAS, Helicoverpa armigera, DENGAN MEMPERHITUNGKAN KEBERADAAN PREDATOR PADA KAPAS

2020 ◽  
Vol 14 (2) ◽  
pp. 72
Author(s):  
NURINDAH NURINDAH ◽  
DWI ADI SUNARTO
Keyword(s):  
Gossypium Hirsutum ◽  
Pest Control ◽  
Natural Enemies ◽  
Helicoverpa Armigera ◽  
Threshold Level ◽  
Cotton Production ◽  
Gossypium Hirsutum L ◽  
Action Threshold ◽  
Helicoverpa Armígera ◽  
Predatory Mirid

ABSTRAK<br />Helicoverpa armigera adalah salah satu hama utama pada kapas,<br />sehingga perlu dikendalikan. Konsep ambang kendali sebagai salah satu<br />komponen dalam PHT telah dikembangkan untuk H. armigera, namun<br />hanya berdasarkan populasi hama dan belum mempertimbangkan<br />keberadaan musuh alami. Penelitian ini bertujuan untuk menguji ambang<br />kendali H. armigera dengan mempertimbangkan keberadaan musuh alami<br />pada skala luas di daerah pengembangan dengan menggunakan lahan<br />petani. Penelitian ini dilakukan pada pertanaman kapas tumpangsari<br />dengan kedelai yang ditanam sesudah padi di Kecamatan Mantup dan<br />Kembangbau, Lamongan, Jawa Timur pada Maret-Oktober 2005. Lahan<br />yang digunakan seluas 15 hektar, di bawah pengelolaan 36 petani.<br />Pengujian ambang kendali H. armigera dilakukan dengan menerapkan dua<br />perlakuan konsep ambang kendali yang merupakan bagian dari PHT<br />kapas, yaitu: (1) AKH: 4 tanaman terinfestasi/25 tanaman contoh; dan (2)<br />AKH+MA: 4 tanaman terinfestasi/25 tanaman contoh; jumlah tanaman<br />yang terinfestasi yang teramati dikurangi 1 jika ditemukan 8 ekor predator<br />dan kelipatannya. Jika populasi pada petak perlakuan mencapai ambang<br />kendali, dilakukan penyemprotan dengan Ekstrak Biji Mimba (EBM).<br />Setiap lahan petani dibagi dua, setiap bagian menerapkan satu perlakuan<br />(n=36). Pengamatan dilakukan pada 25 unit pengamatan per 1,0 ha yang<br />diambil secara W sampling, setiap 7 hari sejak 50 hari setelah tanam (hst)<br />hingga 90 hst. Satu unit pengamatan adalah 1 m 2 . Parameter yang diamati<br />secara periodik adalah populasi H. armigera (telur dan larva); kerusakan<br />buah, hasil kapas berbiji, serta penggunaan saprodi dan tenaga kerja untuk<br />pengendalian hama. Data yang diperoleh dianalisa dengan menggunakan<br />uji t. Hasil penelitian menunjukkan bahwa populasi H. armigera pada<br />kapas + kedelai dapat ditekan oleh musuh alaminya, khususnya kompleks<br />predator yang terdiri atas laba-laba, kumbang kubah dan kepik mirid.<br />Populasi kompleks predator dapat mencapai 40-80 ekor/25 tanaman.<br />Dengan demikian, penerapan ambang kendali H. armigera pada kapas +<br />kedelai dengan memperhitungkan keberadaan predator menyebabkan tidak<br />perlu dilakukannya penyemprotan insektisida sama sekali, sehingga<br />terdapat keuntungan ekonomis, yaitu penghematan biaya saprodi sebesar<br />Rp 259.000 per hektar dan keuntungan ekologis, yaitu tidak tercemarnya<br />lingkungan oleh senyawa toksik.<br />Kata kunci : Kapas, Gossypium hirsutum L., ambang kendali, Helicoverpa<br />armigera, Jawa Timur<br />ABSTRACT<br />Action  threshold  for  Helicoverpa  armigera  by<br />considering the presence of predators on cotton<br />Helicoverpa armigera on cotton was considered as the main pest,<br />therefore it always be a focus of pest control. Action threshold concept as<br />an IPM component had been developed for H. armigera on cotton;<br />however it has not considered the presence of natural enemies. The<br />objective of this research is to test the action threshold of H. armigera by<br />considering the presence of natural enemies on cotton intercropped with<br />soybean in farmers’ fields. The test involved 15 hectares of farmers’<br />fields (involving 36 farmers) in Lamongan, East Java in March-October<br />2005. The action thresholds for H. armigera tested were: (1) AKH: 4<br />infested plants/25 sample plants; and (2) AKH+MA: 4 infested plants/25<br />sample plants, and the number of infested plants observed was subtracted<br />by 1 when 8 predators, and it’s folded up, were found in the sample plants.<br />Spray of neem seed extract (NSE) was applied when the pest population<br />reached action threshold level. Each farmer field was divided into two<br />parts to accommodate the treatments. The observations were made<br />periodically on 25 units per 1,0 hectare in 7-days interval on 50 – 90 days<br />after planting (dap). The size of observation unit was 1 m 2 . Parameters<br />observed included H. armigera population (egg and larva); damage bolls,<br />seed cotton production and the cost of pest control. Data were analysed by<br />using t-test. The results showed that H. armigera population on cotton<br />intercropped with soybean could be repress by its natural enemies,<br />especially by the complex predator (consisted of spiders, lady bird beetles<br />and predatory mirid bugs) to be always under action threshold level. The<br />application of action threshold by considering the presence of predator in<br />cotton + soybean fields would lead to unsprayed cultivation. Resulted<br />economical benefit by saving of the production cost Rp 259.000 per<br />hectare as well as ecological advantage by avoiding of sprays of toxic<br />materials in the environment.<br />Key words : Cotton,  Gossypium  hirsutum  L.,  action  threshold,<br />Helicoverpa armigera, East Java

scholarly journals A review on impact of inflation on economic growth in Nepal

2020 ◽  
Vol 5 (4) ◽  
pp. 576-582
Author(s):  
Seema Karki ◽  
Sushma Banjara ◽  
Amrit Dumre
Keyword(s):  
Economic Growth ◽  
Inflation Rate ◽  
Threshold Value ◽  
Threshold Level ◽  
Target Range ◽  
Economic Activities ◽  
Economic Growth Rate ◽  
High Inflation ◽  
Negative Effect ◽  
The Relationship

This study shows that there is no consensus on the relationship between inflation and economic growth in economic literature. The answer to whether inflation is generally conducive or detrimental to economic growth is still inconclusive. Various arguments have been put forward on both sides. It is generally believed that a low and stable inflation rate helps economic activities, while high inflation hurts growth. The study finds overwhelming support in favor of the specific threshold level of inflation that is appropriate for growth in Nepal. Several studies on this subject have found the threshold value of inflation to be around 6 per cent for Nepal. Inflation is harmful to the economy after certain rate of threshold. Therefore, it is necessary to control inflation in order to address poverty as well as economic growth. Policies need to be put in place to keep inflation target range around the optimum inflation rate to accelerate the pace of economic growth rate and ensure that the negative effect inflation has on economic growth is minimized.

Ion Implantation Doping of Semi-Insulating Polycrystalline Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
Salvatore Lombardo ◽  
S. U. Campisano
Keyword(s):  
Grain Boundary ◽  
Polycrystalline Silicon ◽  
Room Temperature ◽  
Thermionic Emission ◽  
Threshold Value ◽  
Threshold Level ◽  
Room Temperature Resistivity ◽  
Undoped Material ◽  
Donor And Acceptor ◽  
And Diffusion

ABSTRACTThe study of doping of silicon nano-grains in semi-insulating polycrystalline silicon is of paramount importance since intense room-temperature luminescence at 1.54 µm has been demonstrated in this silicon-based semiconductor when doped with erbium ions. We have investigated the formation of p- and n-type layers of semi-insulating polycrystalline silicon by implantation and diffusion of B, P, As, and Er. The room-temperature resistivity can be changed by more than six orders of magnitude for both p- and n-type doping. A dramatic decrease of resistivity is observed for dopant concentrations above a threshold level; this effect is explained by assuming that the free-carrier motion is limited by grain boundary barriers and the electrical conduction is due to thermionic emission and tunneling of the carriers through the barriers. The prevalence of one mechanism over the other depends upon temperature, oxygen concentration and doping. In the undoped material the barrier height is large (≈ 0.5 eV), but for dopant concentrations above the threshold, it decreases with the doping level. Correspondingly, the conductivity increases by many orders of magnitude. The determination of the threshold value allows the evaluation of donor and acceptor grain boundary trap densities. Diodes have been fabricated by implantation and diffusion of boron and erbium. The I-V characteristics of these diodes are interpreted on the basis of the material modeling.

Does the threshold matter? The impact of the monitoring activity on non-performing loans

2019 ◽  
Vol 45 (2) ◽  
pp. 190-221 ◽  
Author(s):  
Domenico Piatti ◽  
Peter Cincinelli
Keyword(s):  
Early Warning ◽  
Performance Indicator ◽  
Positive Impact ◽  
Control Strategies ◽  
Threshold Value ◽  
Threshold Level ◽  
Content Type ◽  
The Impact ◽  
Monitoring Activity

PurposeThe purpose of this paper is to investigate whether the quality of the credit process is sensitive to reaching a particular threshold level of non-performing loans (NPLs) and, more importantly, whether higher NPLs ratios could make the monitoring activity ineffective.Design/methodology/approachThe empirical design is composed of two steps: in the first step, the authors introduce a monitoring performance indicator (MPI) of the credit process by combining the non-parametric technique Data Envelopment Analysis with some financial ratios adopted as input and output variables. As second step, the authors apply a threshold panel regression model to a sample of 298 Italian banks, over the time period 2006–2014, and the authors investigate whether the quality of the credit process is sensitive to reaching a particular threshold level of NPLs.FindingsThis paper finds that, first, when the NPLs ratio remains below the threshold value estimated endogenously, an increase in the quality of monitoring has a positive impact on the NPLs ratio. Second, if the NPLs ratio exceeds the estimated threshold, the relationship between the NPLs ratio and quality of monitoring assumes a positive value and is statistically significant.Research limitations/implicationsDue to the lack of data, the investigation of NPLs in the Italian industry across loan types combined with the monitoring effort by banks management was not possible. The authors plan to investigate this topic in future studies.Practical implicationsThe identification of the threshold has a double operational valence. The first regards the Supervisory Authority, the threshold approach could be used as an early warning in order to introduce active control strategies based on the additional information requested or by on-site inspections. The second implication is highlighted in relation to the individual banks, the monitoring of credit control quality, if objective and comparable, could facilitate the emergence of best practices among banks.Social implicationsA high NPLs ratio requires greater loan provisions, which reduces capital resources available for lending, and dents bank profitability. Moreover, structural weaknesses on banks’ balance sheets still persist particularly in relation to the inadequate internal governance structures. This means that bank management must able to recognise in advance early warning signals by providing prudent measurement together with an in-depth valuation of loans portfolio.Originality/valueThe originality of the paper is twofold: the authors introduce a new proxy of credit monitoring, called MPI; the authors provide an empirical proof of the Diamond’s (1991) economic intuition: for riskier borrowers, the monitoring activity is an inappropriate instrument depending on the bad reputational quality of borrowers.

Targeting Temporal Patterns in Time-Delay Chaotic Systems

2014 ◽  
Vol 24 (02) ◽  
pp. 1450014 ◽  
Author(s):  
Sourav K. Bhowmick ◽  
Dibakar Ghosh ◽  
Pousali Roy ◽  
Syamal K. Dana ◽  
K. Murali ◽  
...  
Keyword(s):  
Chaotic Systems ◽  
Temporal Patterns ◽  
Threshold Value ◽  
Threshold Level ◽  
Control Of Chaos ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
State Variable ◽  
Potential Applications ◽  
Single State

We report a control of chaos in time-delayed nonlinear systems, which constitute an important class of infinite-dimensional systems. Our method simply entails clipping of a single state variable of the chaotic system to a threshold value. The method is easier to implement since only a single variable is needed to be accessible for measurement and resetting. A variation of the threshold level yields a wide variety of regular temporal patterns. The important advantage of this method is that it generates a look-up table, which can be readily used to obtain a desired behavior by just setting the corresponding threshold value. Such a feature makes this control of chaotic systems attractive for potential applications. We physically verify the technique in an electronic experiment.

scholarly journals Accurate hematopoietic stem cell frequency estimates by fitting multicell Poisson models substituting to the single-hit Poisson model in limiting dilution transplantation assays

Blood ◽  
2010 ◽  
Vol 116 (14) ◽  
pp. 2472-2475 ◽  
Author(s):  
Thierry Bonnefoix ◽  
Mary Callanan
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Model Averaging ◽  
Poisson Model ◽  
Threshold Value ◽  
Threshold Level ◽  
Hematopoietic Stem ◽  
Gold Standard Method ◽  
Poisson Models ◽  
Limiting Dilution

Abstract Limiting dilution transplantation assay (LDTA) is considered as the gold standard method to assess hematopoietic stem cell (HSC) content. Traditionally, HSC frequency estimates are based on the single-hit Poisson model (SHPM), which posits that one donor HSC is sufficient to generate a progeny of detectable differentiated cells above a threshold value in hosts. However, there is no clear support for this statement, and it is receivable that more than one donor HSC may be necessary to provide detectable reconstitution in hosts above the threshold level for detection, usually 0.5% to 1% of donor-derived cells. To address this hypothesis, we evaluated the ability of a class of multiCell Poisson models (C≥1PMs) to fit to LDTAs. In 7 of the 8 reanalyzed LDTAs, C≥1PMs plausibly compete with the traditional SHPM. Model averaging across the set of plausible models gives 1.32- to 5.88-fold increases in HSC frequencies compared with the SHPM.

scholarly journals Выбор порога селекции сигнала по уровню в обнаружителях с нормализованным индикаторным процессом

2020 ◽  
Author(s):  
S.B. Egorov ◽  
R.I. Gorbachev
Keyword(s):  
False Alarm ◽  
Probabilistic Model ◽  
Numerical Estimate ◽  
Threshold Value ◽  
Threshold Level ◽  
Probability Of False Alarm ◽  
Autonomous Mode ◽  
The Mean ◽  
The Moment

Предложена вероятностная модель работы автономного обнаружителя на этапе ожидания сигнала, когда момент появления сигнала неизвестен и по этой причине решающая статистика, сравниваемая с порогом, формируется непрерывно во времени в режиме скользящего окна . Ложная тревога в этом случае эквивалентна появлению хотя бы одного выброса помехового индикаторного процесса выше порога на максимально возможном интервале ожидания сигнала. Высота порога такова, что ложные выбросы являются редкими событиями, подчиняющимися закону Пуассона. На основе такой вероятностной модели показано, что вероятность ложной тревоги равна среднему числу ложных выбросов на максимально возможном интервале ожидания сигнала. Для обнаружителей с нормализованным индикаторным процессом получены соотношения, определяющие порог селекции сигнала по заданной вероятности ложной тревоги на заданном максимально возможном интервале ожидания сигнала. Показано, что в определении порога важную роль играет средняя квадратичная частота флюктуаций помехового индикаторного процесса. Дана численная оценка увеличения порога по сравнению с его значением, определенным по вероятности ложной тревоги в точке . Показано, что определение порога по предложенной методике особенно актуально для обнаружителей, работающих в длительном автономном режиме.This article proposes a probabilistic model of the autonomous detector in standby mode, when the moment of the signal appearance is unknown and for this reason the decisive statistics is generated continuously in time in the sliding window mode and compared with the threshold value. In this case, false alarm is equivalent to the appearance of at least one outlier of the jamming indicator process above the threshold at the maximum possible signal waiting interval. The threshold level match case when the false alarm are rare events and obey the Poisson law of distribution. Based on such a probabilistic model, we show that the probability of a false alarm is equal to the average number of false emissions at the maximum possible interval for a signal waiting. For detectors with a normalized indicator process, are obtained relations that determine the threshold for signal selection by a given probability of false alarm at a given maximum possible signal waiting interval. It is shown that in determining the threshold, the mean square frequency of fluctuations of the interference indicator process plays an important role. Also, a numerical estimate of the increase in the threshold is given compared with its value determined by the probability of false alarm at a point . It is shown that the determination of the threshold by the proposed method is especially relevant for detectors operating in a long autonomous mode.

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