133 research outputs found

    Application of proximal sensing techniques for epidemiological investigations of <em>Fusarium </em>head blight in wheat under field and controlled conditions

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    Sensors can provide valuable insight into studying the physiological disorder due to plant pathogens. Fusarium head blight (FHB) influences the optical properties of wheat (Triticum aestivum L.) at canopy and ear levels. This research aimed to investigate these complex disease situations under field as well as controlled conditions with the application of proximal sensing systems. Observations under field conditions revealed that the presence of foliar diseases is associated with higher Fusarium infection in the wheat canopy (cv. Tobak and Pamier), which might be attributed to reduced defence mechanisms. This was reflected in increased FHB incidence visually assessed at growth stage (GS) 83. Fungicides applied against foliar diseases before anthesis reduced FHB presence, which might be not only due to reducing the available inoculum in the canopy but also due to promoting defenses against Fusarium infection. Furthermore, prediction of FHB through spectral parameters such as blue-green index 2 (BGI2) and photochemical reflection index (PRI) proved to be very promising. At ear level, development of Fusarium infection is dependent on the primary infection site within ears and the prevailing environmental conditions after infection. Such a relationship was verified under controlled conditions after tip, centre and base inoculations, separately, by F. graminearum and F. culmorum of wheat ears (cv. Passat). Symptom dynamics (FHB index) were slower downwards within ears in comparison to the upward development. In contrast to the symptom appearance the infection of Fusarium species proved to be directed basipetally – a rare development of fungal infections. According to these observations it could be revealed that higher temperatures accelerated the ripening of ears and allowed these plants to escape the infection within ears. In contrast, at lower temperatures, higher disease severity was observed even for tip infection. Infrared thermography could predict this primary site of ear infection through temperature span within ears and enabled disease detection before symptoms became visible. The temperature difference between air and ear was negatively correlated to FHB index and allowed disease detection at early senescence stage. Combining the features of thermal measurements and chlorophyll fluorescence images proved to present a high potential in characterising FHB at spikelet level. Discriminating spikelets infected with F. graminearum from those infected with F. culmorum were enabled up to 100% accuracy by fusion of sensor data. This study demonstrated that FHB is influenced by foliar wheat diseases when at low severities of both. The control of leaf pathogens by fungicides can play an important part in integrated disease management – also against Fusarium infections. It could also be confirmed that primary infection sites within ears and the prevailing environmental conditions after infection are key factors which determine the later development of FHB. Sensors proved to be useful in monitoring and assessing FHB under field conditions – detailed investigations under controlled conditions provided more profound insights in this regard. The findings of this research contribute to more efficient control of FHB using the concepts of remote sensing to improve precision plant protection and may be applied in selection processes of breeding for FHB resistance as well.Geeignete Sensoren können einen wertvollen Einblick in die physiologischen Verhältnisse in Pflanzen bieten, wenn diese von pathogenen Organismen heimgesucht werden. Die Infektionen von Getreide durch Fusarium Arten (Fusarium Head Blight = FHB) verändern die optischen Eigenschaften von Wirtspflanzen – vor allem von Weizen (Triticum aestivum L.) – sowohl im Getreidestand als auch auf dem Niveau der einzelnen Ähren. Die vorliegenden Untersuchungen hatten zum Ziel, die näheren Gegebenheiten dieser komplexen Befallssituationen im Freiland und unter kontrollierten Bedingungen durch die Anwendung von zerstörungsfreien Messmethoden zu charakterisieren. Erhebungen im Feld machten deutlich, dass der Befall mit Fusarium Arten durch das Auftreten weiterer Blattkrankheiten im Weizenbestand gefördert wurde. Dies wurde beispielhaft an den Sorten „Tobak“ und „Pamier“ ermittelt und deutet auf eine geringere Widerstandsfähigkeit der Pflanzen gegenüber Fusariosen bei multiplem Befall hin. Dies konnte im Wachstumsstadium 83 (BBCH-Skala) auch makroskopisch festgestellt werden. Fungizidanwendungen, die vor der Blüte durchgeführt wurden, konnten das Auftreten der Fusarien am Weizen reduzieren. Dies war zweifellos auf die Reduktion des verfügbaren Inokulums der Fusarium-Arten zurückzuführen. Zugleich kann angenommen werden, dass durch die Gesunderhaltung der Blattfläche auch eine erhöhte Widerstandsfähigkeit der Pflanzen gegenüber Fusariosen hervorgerufen werden. Die Möglichkeit zur Vorhersage von FHB durch spektrale Parameter konnte bestätigt werden – vor allem an Hand des Blue- Green-Index 2 (BGI2) und des photochemischen Reflektionsindexes (PRI) erwiesen sich als besonders geeignet. An der Getreideähre ist die Entwicklung der Fusariosen in hohem Maße abhängig von dem primären Infektionsort und den nachfolgenden Umweltbedingungen im Anschluss an die Primärinfektion der Ähre. Dies konnte unter kontrollierten Bedingungen am Weizen der anfälligeren Sorte „Passat“ für Primärinokulationen an der an der Spitze, in der Mitte und an der Basis der Ähren nachgewiesen werden. Es zeigte sich, dass die Symptomentwicklung (FHB index) in der Ähre deutlich weniger nach unten gerichtet war, als in der Zone oberhalb des Inokulationspunktes. Dies galt sowohl für Infektionen durch F. graminearum als auch für F. culmorum. Im Gegensatz zur Symptomentwicklung entwickeln sich die Fusariosen vor allem abwärts in der Ähre – ein durchaus eher seltener Prozess für pflanzenpathogene Organismen. Erhöhte Temperaturen beschleunigen die Reifung der Ähren – obwohl günstig für das Auftreten von Fusariosen ermöglichen diese Bedingungen auch ein „disease escape“ gegenüber Fusarium-Arten. Bei niedrigeren Temperaturen führen die Infektionen zu deutlich höheren Infektionsraten, weil mehr Zeit zur Ausbreitung besteht – selbt in den Ährenspitzen. Mit Hilfe der Infrarot-Thermographie gelang es, die Primärinfektionen in der Ähre durch die Temperaturdifferenz zwischen Umwelt und den biologisch relevanten Zonen zu charakterisieren bevor bereits makroskopisch Symptome erkennbar wurden. Die Gewebetemperaturdifferenzen waren negativ korreliert mit dem FHB index – sie erlaubten aber auch eine Bestimmung des Reifestatus der Ähren. Wurden die Infrarotmessungen mit der Messung von Chlorophyllkorrelierten Messungen zerstörungsfrei kombiniert, lies sich damit eine hohe Korrelation identifizieren – insbesondere auf dem Niveau der einzelnen Ährchen. Wurden diese Beziehungen betrachtet, dann zeigte sich, dass sich sogar Unterschiede zwischen F. graminearum und F. culmorum erkennen ließen. Die vorliegenden Untersuchungen zeigen, dass das Auftreten von Fusariosen an Getreide auch in besonderem Umfang durch andere Blattkrankheiten gefördert wird – erkennbar allerdings nur bei geringen Befallsintensitäten. Die Förderung der Pflanzengesundheit – auch durch Fungizide – kann zu einer wichtigen Funktion im Integrierten Pflanzenschutz führen – sicher auch zum Schutz vor Ährenfusariosen. Es konnte nachgewiesen und durch Anwendung geeigneter Sensoren genutzt werden, dass die Fusarium-Infektionen eine besondere Rolle spielen. Vor allem die Primärinfektionsorte, die sehr umweltabhängig sind – haben großen Einfluss auf die Schadwirkung. Sensoren können offenbar sehr hilfreich bei dem Erkennen und der Befallsbestimmung – und das bereits unter Freilandbedingungen. Dies wurde durch Erhebungen unter Feldbedingungen bestätigt – ergänzt durch weitere Untersuchungen unter praktischen Bedingungen. Die vorliegenden Ergebnisse und Erkenntnisse können eine effizientere Unterdrückung von FHB ermöglichen. Dabei geht es darum, dass die Elemente des „sensing of diseases“ einerseits in den Integrierten Pflanzenschutz eingebunden werden können und zudem auch für Selektionsprozesse in der Züchtung zur Vermeidung von FHB genutzt werden kann

    Individual Determinants of IT Occupational Outcomes

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    Extant research in information systems relies heavily on career anchor theory (CAS) as a lens to examine occupational choices and outcomes in information technology. Yet, the empirical results are inconclusive, and the power of the theory in predicting IT occupations is rather weak. With the growing demand for IT professionals, we need to examine other factors that can predict the IT occupational outcomes. In this paper, we draw on social cognitive career theory (SCCT) and examine self-efficacy as a complementary factor to career anchors in predicting whether seekers end up with technical, business, or managerial occupations in IT. Specifically, we propose and test a model that combines variables from both CAS and SCCT theories. We use multiple discriminant analysis to measure the extent to which variables from both theories discriminate the IT occupations. The results show that our model predicts occupations with an accuracy rate of 82.2 percent (compared to 75.2 percent for the original CAS model). Our results also show that individuals who hold a professional role that matches their profile are more satisfied than those who do not. Lastly, we discovered that, from individuals who hold a position that does not match their profile, business-IT professionals are most satisfied

    The role of environmental conditions and purchasing power parity in determining quality of life among big Asian cities

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    This article has examined the role of environmental conditions and purchasing power parity in deciding the quality of life among big Asian cities. The study has constructed an index for quality of life with the help of housing, crime rates, death rate, average life expectancy, environmental degradation, and level of education. Quality of life has been selected as the dependent variable and the level of pollution, availability of health care facilities, local purchasing power, availability of groceries, level of democracy, cost of living, restaurants, level of traffic, and level of rents are selected explanatory variables. For empirical analysis, this study uses data for the years 2017, 2018, and 2019. The estimated results show that pollution has a negative and significant impact on the quality of life in the case of Asian cities. Local purchasing power has a positive and significant relationship with the quality of life in the cities of Asia. Groceries and democracy are very important parts of the daily life of human beings but they have insignificant impacts on the quality of life in Asian cities. Restaurants have a positive and significant impact on quality of life. This study finds that level of traffic and the level of rent have a negative and significant impact on the quality of life in the case of Asian cities. The overall results conclude that selected indicators play a significant role in determining the quality of life in Asian cities

    The role of environmental conditions and purchasing power parity in determining auality of life among big Asian cities

    Get PDF
    This article has examined the role of environmental conditions and purchasing power parity in deciding the quality of life among big Asian cities. The study has constructed an index for quality of life with the help of housing, crime rates, death rate, average life expectancy, environmental degradation, and level of education. Quality of life has been selected as the dependent variable and the level of pollution, availability of health care facilities, local purchasing power, availability of groceries, level of democracy, cost of living, restaurants, level of traffic, and level of rents are selected explanatory variables. For empirical analysis, this study uses data for the years 2017, 2018, and 2019. The estimated results show that pollution has a negative and significant impact on the quality of life in the case of Asian cities. Local purchasing power has a positive and significant relationship with the quality of life in the cities of Asia. Groceries and democracy are very important parts of the daily life of human beings but they have insignificant impacts on the quality of life in Asian cities. Restaurants have a positive and significant impact on quality of life. This study finds that level of traffic and the level of rent have a negative and significant impact on the quality of life in the case of Asian cities. The overall results conclude that selected indicators play a significant role in determining the quality of life in Asian cities

    Recognizing Different Foot Deformities Using FSR Sensors by Static Classification of Neural Networks

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    تُعَدُّ أنظمة النعال الحسّاسة للحركة تقنية واعدة للعديد من التطبيقات في الرعاية الصحية والرياضة. حيث يمكن أن توفّر هذه الأنظمة معلومات قيّمة حول توزيع الضغط على القدم وأنماط المشي لأفراد مختلفين. ومع ذلك، فإن تصميم وتنفيذ مثل هذه الأنظمة يواجه العديد من التحديات، مثل اختيار الحسّاسات والمعايرة ومعالجة البيانات والتفسير. في هذه الدراسة، نقترح نظام نعل حساس باستخدام مقاومات استشعار القوى  لقياس الضغط المطبّق من القدم على مناطق مختلفة من النعل. يقوم هذا النظام بتصنيف أربعة أنواع من تشوهات القدم: طبيعي، مسطح، انحراف القدم إلى الداخل، وزيادة انحراف القدم إلى الخارج. تستخدم مرحلة التصنيف قيم الضغط الفرقية على نقاط الضغط كمدخلات لنموذج التغذية الأمامية للشبكات العصبية. تم جمع البيانات من 60 فرداً تم تشخيصهم بالحالات المدروسة. حقق تنفيذ التغذية الأمامية للشبكات العصبية دقة بنسبة 96.6٪ باستخدام 50٪ من المجموعة البيانية كبيانات تدريبية و 92.8٪ باستخدام 30٪ من البيانات التدريبية فقط. ويوضح المقارنة مع الأعمال ذات الصلة الأثر الإيجابي لاستخدام القيم الفرق لنقاط الضغط كمدخلات للشبكات العصبية مقارنة بالبيانات الأولية.Sensing insole systems are a promising technology for various applications in healthcare and sports. They can provide valuable information about the foot pressure distribution and gait patterns of different individuals. However, designing and implementing such systems poses several challenges, such as sensor selection, calibration, data processing, and interpretation. This paper proposes a sensing insole system that uses force-sensitive resistors (FSRs) to measure the pressure exerted by the foot on different regions of the insole. This system classifies four types of foot deformities: normal, flat, over-pronation, and excessive supination. The classification stage uses the differential values of pressure points as input for a feedforward neural network (FNN) model. Data acquisition involved 60 subjects diagnosed with the studied cases. The implementation of FNN achieved an accuracy of 96.6% using 50% of the dataset as training data and 92.8% using only 30% training data. The comparison with related work shows good impact of using the differential values of pressure points as input for neural networks compared with raw data

    The role of terrorist events in determining stock returns in Pakistan: covering most vibrant era 2003-2013

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    This study explains the relationship and significance of terrorism attacks and Pakistan Stock Exchange behavior. This study uses standard event study methodology and data relating to the stock market index was collected from the website of the Pakistan Stock Exchange and data relating to terrorist events was collected from the newspapers of Business Recorder and DAWN. A total of 277 terrorist events have been considered in this study. The first-day abnormal return, five-day cumulative abnormal return, and ten-day cumulative return were calculated for all of the events. Terrorist events have been analyzed year-wise and also on the bases of their category like events related to foreigners, military, politics, and general terrorist events. This study finds evidence that terrorist events affect the stock market in Pakistan. But their impact is different considering the economic and political implications of these events. Terrorist events yield mixed results where the significance of the events differed considerably in their impact on the stock market. Moreover, the abundance of terrorist events also hindered the estimation as rare events bring the element of surprise and the market adjusts to more frequent events inappropriate manner. However, terrorist events relating to politics and foreigners yield more consistent results as these events were distributed across time with longer intervals. Overall, this study lays the foundation to make further explorations into the phenomenon of uncertainty caused by terrorist events in relevance to the stock market in Pakistan. Implications and directions for future research are also provided at the end of the study

    Prevalence of anxiety and depressive symptoms in ulcerative colitis patients in Jordan and its relationship to patient-reported disease activity

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    Inflammatory bowel disease is associated with higher rates of anxiety and depression compared to the general population. We aimed to determine the prevalence of anxiety and depressive symptoms among patients with ulcerative colitis and correlation to disease activity. In this cross-sectional study, we collected data from 70 consecutive ulcerative colitis patients over one year at our inflammatory bowel disease outpatient clinic through an interview and a questionnaire containing patient demographics and disease characteristics. Anxiety and depressive symptoms were characterized using the Generalized Anxiety Disorder-7 questionnaire and Patient Health Questionnaire-9, respectively, with ulcerative colitis disease severity assessed by the Partial Mayo scoring system. The majority of our patients were females (68.6%) and the mean age was 39.3 years. Rates of anxiety and depressive symptoms among ulcerative colitis patients were 65.7% and 58.6%, respectively. Depressive symptoms were significantly associated with patient-reported disease activity (r = 0.361; p = 0.010). Significant percentages of ulcerative colitis patients were appreciated to have anxiety and depressive symptoms, and there was a correlation between patient-reported disease activity and depressive symptoms. At this high rate of prevalence, it is justified to screen patients for the presence of psychiatric comorbidities

    Numerical evaluation of thermal comfort in traditional courtyards to develop new microclimate design in a hot and dry climate

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    The growing interest in thermal comfort of outdoor environments yields in different analysis on courtyards as a common space between urban and architectural scales. However, there is a limited knowledge regarding the microclimatic behavior of such spaces. Using ENVI-met simulations, this paper aims to numerically discuss the thermal performance of different configurations of traditionally designed courtyards in Shiraz, Iran, which experiences hot summers and cold winters. The geometrical effects such as orientation and H/W (height to width ratio) of courtyards are considered as potential parameters to improve the microclimatic conditions. In this paper, PMV and UTCI are used as thermal comfort indices. The obtained results indicate mean radiant temperature and wind speed as the most effective parameters for thermal comfort of courtyards. In addition, the aforementioned geometrical parameters might not be able to solely create a desirable condition, but they could significantly improve the thermal comfort of courtyards during summer and winter. To achieve a desirable thermal comfort level, the results suggest using configurations of a high H/W rate and southward orientation in order to obtain better shading during summer as well as allowing the solar radiation in while regulating the wind speed in winter

    Characterization of greater middle eastern genetic variation for enhanced disease gene discovery

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    The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics
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