Quality Of Stock Research Articles

Using Support Vector Machines classification to differentiate spectral signatures of potato plants infected with Potato Virus Y

Potato Virus Y (Potyviridae, PVY) has resulted in significant economic harm to potato (Solanum tuberosum) farmers and has disrupted seed supplies to commercial growers, especially in varieties with beneficial processing and marketing attributes but high disease susceptibility such as Russet Burbank and Russet Norkotah varieties. Commercial growers rely entirely on seed producers and certification systems to get disease-free seed as they have no recourse to mitigate seed-borne PVY after the seed is planted. Potato seed stock producers currently utilize intensive pesticide applications to suppress insect vectors and human-resource intensive activities where workers visually inspect and remove suspect infected plants during the growing season. Industry stakeholders also depend upon extensive field and tuber sampling coupled with off-season growouts and laboratory testing to ascertain infection levels within certification programs. Despite these efforts, seed producers and certification agencies are currently unable to control PVY infection in the industry’s seed pipeline, and this has a significant impact on commercial markets and regional economies. The industry also lacks a consistent, scalable, accurate, and robust detection system capable of assessing every plant within the seed potato production agro-ecosystem during the production season. Remote sensing technologies coupled with machine learning classifiers are a significant leap forward in the detection and differentiation of plant disease incidence. The continuing advancement of unmanned aerial systems (UAS) and unmanned ground vehicles provide access to high spatial, temporal, and spectral resolution instrumentation with which to monitor dynamic agricultural production systems at a leaf-scale resolution. In this study, we demonstrate PVY-infected potato plants in an agricultural production field produce different spectral reflectance profiles in comparison to neighboring non-infected plants. The Support Vector Machines (SVM) classifier differentiated spectral reflectance curves of PVY-infected and non-infected plants at an accuracy of 89.8% using near infrared and shortwave infrared wavelengths. The classification accuracy dropped to 46.9% using red, green, and blue wavelengths that the industry currently utilizes to detect diseased plants visually. This research shows that remote sensing and machine learning classifiers outperform current industry standards and have the potential to greatly enhance PVY detection efforts resulting in improved potato seed stock quality necessary to maximize yields.

The Cross-Sectional Spillovers of Single Stock Circuit Breakers

This paper uses transaction data to estimate how single stock circuit breakers on the London Stock Exchange affect other stocks that remain in continuous trading. This “spillover” effect is estimated by calculating the effect of a trading halt on the market quality of stocks that remain in continuous trading and comparing this with the effect of a stock whose absolute returns are of a magnitude nearly sufficient to trigger a trading halt but do not do so. Market quality is measured using a combination of trading costs, volatility and volume. In the two-month period we study, characterized by a relatively volatile trading environment, we find that circuit breakers lead to a significant improvement in the liquidity, and reduction in the volatility, of stocks that remain in continuous trading. This suggests that — at least over the period covered by our data — single stock circuit breakers can play an important role in reducing the spillover of poor market quality across stocks.

COMPARATIVE ANALYSIS OF BATTERY CAGE AND DEEP LITTER POULTRY HOUSINGSYSTEMS IN ABIA STATE, NIGERIA

The study was centered on the comparative analysis of battery cage and deep litter poultry housing systems in Abia state, Nigeria. The study specifically examined the factors influencing the choice of poultry housing system in the study area; estimated the profitability of battery cage and deep litter system in the area; analyzed the determinants of profit in battery cage and deep litter systems respectively; and examined the constraints faced by poultry farmers in the area. Primary data source was used for the study. Multi-stage sampling technique was used in the selection of 140 respondents. Descriptive statistics like frequency, tables, charts, etc; profitability index (cost and returns analysis) and multiple regression were the tools of analysis. From the cost and return analysis, it was observed that both housing systems are profitable. The t test result showed that housing system adopted for poultry farms have an effect on the profit. However, it was observed that farmers using deep litter system make more profit when compared to battery cage housing system. It was observed that battery cage system is more capital intensive when compared to deep litter system and this predisposes most famers to favour deep litter housing system to battery cage system. Sex, marital status, education, mortality rate, cost of production, farm size, experience and access to credit were significant variables having varying effects on the profit of battery cage users while sex, household size, education, mortality, cost of production, farm size, experience were the significant variables influencing the returns of deep litter users in the study area. High cost of feeds, inadequate amenities, high interest rates, quality of stock etc. where the major constraints of poultry production in the area. The study recommends that governments should subsidize the cost of feeds to make it affordable for farmers in the study area

Aflatoxin B1 (AFB1) induced dysregulation of intestinal microbiota and damage of antioxidant system in pacific white shrimp (Litopenaeus vannamei)

Aflatoxins, especially aflatoxin B1 (AFB1), exert a substantial impact on the shrimp farming production, inducing disease with a gradual decline of reared shrimp stock quality and profitability, thus causing a significant problem in aquaculture systems. In order to investigate the influence of AFB1 on intestinal health and antioxidant system, we monitored the dynamic change of intestinal microbiota of pacific white shrimp (Litopenaeus vannamei) at 3-, 6-, 12-, 18-, 24- and 30-d after AFB1 challenge. Meanwhile, we determined the activities of several important antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and the content of malondialdehyde (MDA) in the intestines and hepatopancreas. The results showed that, the types of intestinal microbiota in the control group are more abundant than the experimental group both at the phyla level and genera level. At the phyla level, the relative abundance of Proteobacteria and Firmicutes in the experimental group increased obviously with the culture days extension, while the relative abundance of Bacteroidetes decreased. At the genera level, the relative abundance of Vibrio and Photobacterium in the experimental group increased evidently, while the relative abundance of Flavobacterium_sp_M and Tenacibaculum decreased. The CAT, SOD and GPX activities of intestinal and hepatopancreas were significantly higher in the experimental group than in the control group, and showed a tendency to increase first and then decrease as a whole while the content of MDA changes on the contrary. All above findings suggested that AFB1 could induce dysregulation of intestinal microbiota and damage of antioxidant system in pacific white shrimp (Litopenaeus vannamei).

Development of an objective and uniform scoring method to evaluate the quality of rearing in Dutch dairy herds

Young stock rearing is an essential part of dairy management, and it is important that the quality of rearing can be monitored and altered if necessary. In this study, a young stock rearing quality system (KalfOK) was developed with the aim to provide an objective and standardized means to evaluate and monitor the quality of young stock rearing in Dutch dairy herds. In the project, 201 dairy farmers participated. Twelve key indicators were defined that were related to calving and successful rearing, antimicrobial use, and herd health. For each of the key indicators, the value was calculated per herd and quarter of the year between January 2014 and April 2017. Benchmark values were determined to compare herd-specific results and for selection of threshold values. Each of the key indicators was graded when the value scored above the threshold. Combining the grades resulted in the herd-specific KalfOK score, which could vary between 0 and 100. Subsequently, 100 of the participating dairy herds were visited and the quality of young stock rearing was scored by a trained veterinarian. Using principal component analysis, the results of the herd health checks were combined into a factor score that represented the observed quality of young stock rearing during the visit. The amount of variance in observed quality of rearing during the herd health check that was explained by the key indicators in KalfOK was evaluated. Additionally, the validity of KalfOK to distinguish herds with an excellent or insufficient quality of young stock rearing was assessed by comparing the top and bottom 10% herds in the herd health check with the proportion of herds with a KalfOK score above or below a prespecified cutoff value. The results of the linear regression model showed that the key indicators included in KalfOK accounted for 56% of the variation in the score of the herd visits by a veterinarian. The moving average of the annual KalfOK score, which was the sum of the grades of all key indicators, was 77 points (25th percentile = 71, 75th percentile = 85 points). The combination of the sensitivity (88%, 95% confidence interval = 47-100%) and specificity (67%, 95% confidence interval = 54-78%) of KalfOK to correctly classify herds with an excellent quality of young stock rearing was highest when a cutoff value of 80 points was applied. Detection of dairy herds with an insufficient quality of young stock rearing was best at a cutoff value of 70 points (sensitivity 86%, 95% confidence interval = 42-100%; specificity 77%, 95% confidence interval = 66-86%). The KalfOK score that was based on routinely collected herd data provided an indication of the quality of young stock rearing in individual Dutch dairy farms. The KalfOK score illustrates how such data can be transferred into herd-specific information in support of animal health and welfare. Given the increasing availability of automatically assembled data, the development of similar monitoring tools seems a feasible option to enhance herd-specific management.

Exchange Competition with Levelled Speed

After a long period of high-speed trading, exchanges are now trying to slow down trading with speed bumps. We study how this market design innovation affects traders’ reaction times, the market quality of stocks, and the operators of competing exchanges. Post speed bump, we find slower reaction times to order book events, and depth changes consistent with reduced order detection and back-running. Reduction in quote-to-trade ratio and flickering quotes improves market quality. Exchanges without planned speed bumps lose market share, with reduced return on assets, stock returns, and enterprise value. Their stocks become attractive for short sellers.

Rethinking Decimalization The Impact of Increased Tick Sizes on Trading Activity and Volatility

In this study, we examine the trading activity and volatility of stocks influenced by the US Securities and Exchange Commission’s pilot program that increased tick sizes for various samples of stocks. The objective of the program is to examine possible improvements to the market quality of small-cap stocks, which have historically been less liquid than larger-cap stocks. Using a difference-in-difference approach, we find that, relative to control stocks, the trading activity of pilot stocks does not appear to be meaningfully affected by the increase in tick sizes. Volatility, however, increases markedly for the pilot stocks vis-a-vis other stocks. These results are robust to the different sets of pilot stocks, various rollout periods, and different control groups.

Stocktype and Vegetative Competition Influences on Pseudotsuga menziesii and Larix occidentalis Seedling Establishment

Douglas fir (Pseudotsuga menziesii var. glauca (Mayr) Franco), and western larch (Larix occidentalis Nutt.) are species of ecological and commercial importance that occur throughout the Western United States. Effective reforestation of these species relies on successful seedling establishment, which is affected by planting stock quality, stocktype size, and site preparation techniques. This study examined the effects of container volume (80, 130, 200, and 250 cm3) and vegetative competition on seedling survival and physiological and morphological responses for two years, post-outplanting. Glyphosate application (GS) and grass planting (HC) were used to achieve low and high levels of competition. For all measured attributes, the container volume × vegetative competition was not significant. Mortality was strongly influenced by competition, with higher mortality observed for Douglas fir and western larch planted in HC plots one (28% and 98%) and two (61% and 99%) years following outplanting. When competition was controlled, seedlings of both species exhibited greater net photosynthesis (>9 μmol m−2 s−1), greater predawn water potential (>−0.35 MPa), and lower mortality (2–3%) following one year in the field, indicating establishment success. The 80 cm3 stocktype remained significantly smaller and exhibited lower growth rates for the duration of the study, while all other stocktypes were statistically similar. Our results demonstrate the importance of controlling vegetative competition regardless of stocktype, especially for western larch, and suggest that benefits to post-planting seedling physiology and growth in relation to container size plateau beyond 130 cm3 among the investigated stocktypes.

Fragmentation and Market Quality: The Case of European Markets

This paper questions whether the proliferation of alternative trading venues in Western Europe after MiFID implementation in 2007 affected market quality. By means of a difference-in-differences analysis, we evaluate changes in market quality of stocks that initiated trading in Multilateral Trading Facilities (MTF) in relation to matched samples. Our analysis provides evidence that the overall liquidity (measured by transaction costs and price impact) and trading activity increased in the short term with trade initiation in MTF. Notably, we show that fragmentation did not cause lower price precision or informativeness, but some tests suggest that fragmentation correlates positively with volatility. The results of this study are stronger for stocks with greater propensity for MTF trade initiation, i.e. stocks with greater size and liquidity prior to that event. Interestingly, the impact on liquidity and trading activity varied across stock exchanges and timing of MTF trade initiation. As for long run effects, our results suggest an improvement of overall liquidity and a neutral effect on the trading activity of traditional exchanges.

Cognitive skills and economic performance: evidence from the recent international student assessment tests

This paper examines the empirical relationship between the quality of educational attainment and economic growth. It uses country scores from the recent international student assessment tests as a proxy for education quality and cognitive skills of the labor force along with data on education quantity (schooling) and several control variables. The student assessment data set includes two widely used international tests, PISA and TIMSS, spanning the periods 2000–2015, and 1995–2015, respectively. Empirical results from OLS and IV estimations indicate that cognitive skills component of human capital has a robust positive effect on growth performance whereas the impact of average years of schooling, after conditioning on test scores, is statistically insignificant. Results suggest that to improve the quality of human capital stock and spur economic growth, countries should focus more on developing national education policies designed to enhance students’ cognitive skills rather than merely increasing the number of schools.

Udogodnienia miejskie – element publicznego wymiaru zasobów mieszkaniowych

W dyskusji o publicznym wymiarze zasobów mieszkaniowych ważnym elementem są miejskie udogodnienia. Stanowią one istotną część tak zwanego sąsiedztwa mieszkaniowego i są publiczne w tym sensie, że są źródłem korzyści zewnętrznych wpływających na użyteczność mieszkań i jakość zamieszkania w mieście. W konsekwencji kształtowanie miejskich udogodnień może wpływać pozytywnie na skuteczność prowadzonej polityki mieszkaniowej. Z punktu widzenia badań nad udogodnieniami miejskimi wyzwaniem pozostaje jednak stwierdzenie, które udogodnienia są pierwszoplanowe, a które drugorzędne w ocenie jakości zasobów mieszkaniowych. Ponadto w badaniach tych stosowane są nowe podejścia i narzędzia, pozwalające analizować zależności między zasobami mieszkaniowymi a udogodnieniami miejskimi. Niniejszy artykuł stanowi próbę odpowiedzi na pytanie o wpływ udogodnień miejskich na jakość zasobów mieszkaniowych. W pierwszej kolejności podejmuje próbę wyjaśnienia pojęć „udogodnienia miejskie” i „sąsiedztwo mieszkaniowe” oraz wskazania ich kluczowych typów i cech charakterystycznych. W dalszej części artykułu zaprezentowano wyniki badania zrealizowanego w Łodzi, prezentującego czynniki satysfakcji z zamieszkania w poszczególnych częściach miasta. Wyniki te pośrednio przyczyniają się do oceny skali wpływu udogodnień miejskich na postrzeganą jakość zamieszkania, jak również potencjalną zmianę miejsca zamieszkania. Otrzymane rezultaty mają charakter inicjalny i mogą stanowić punkt wyjścia do kolejnych, pogłębionych studiów.

Improving the engineering-and-economical performance of ore-thermal electric furnaces in the smelting of silicomanganese

Ways of increase of ore-heating electric furnaces, used for production of silicomanganese, engineering-and-economical performance are analyzed. Questions of data of the electric, thermal and technological modes of the furnace functioning collecting and processing for use in operation of an advanced control system of the furnace providing increase in technical and economic efficiency of technological process and an adaptability to quality of burden stock are considered.

Does Cross-Listing Really Enhance Market Efficiency for Stocks Listed in the Home Market? The Perspective of Noise Trading in the Chinese Stock Market

ABSTRACTThe investor recognition hypothesis and the bonding hypothesis, which help us understand the market quality of stocks that are cross-listed on different stock markets, imply improved market efficiency after cross-listing because of increased investor participation. However, the noise trading of inexperienced investors in the Chinese stock market negatively affects market efficiency. By employing propensity score matching and multivariate regression analysis, we show that the increased individual investor participation actually lowers market efficiency in their home market after cross-listing. This effect is more evident for stocks that were either listed first on the Chinese stock market or listed on the Chinese stock market and the Hong Kong stock exchange (SEHK) on the same date than for stocks that were listed first on the SEHK.

Quality investing in the Indian stock market

PurposeThe purpose of this paper is to explore whether stock selection strategies based on four fundamental quality indicators can generate superior returns compared to overall market.Design/methodology/approachThe sample of stocks comprises the constituents of BSE-500 index, which is a broad based index consisting of highly liquid stocks from all 20 major industries of the Indian economy. Portfolios are constructed on the basis of quality indicator rankings of companies and the returns of these portfolios are compared with the overall market. Excess returns on quality based portfolios are also determined using OLS regressions of quality portfolio returns on market, size, value and momentum factor returns.FindingsThe results suggest that two of the four quality strategies, namely Grantham Quality indicator and Gross Profitability have generated superior returns after controlling for market returns as well as common anomalies such as size, value and momentum. Combining value strategies with quality strategies do not yield any significant gains relative to quality only strategies.Practical implicationsFor investors looking to invest in the Indian stock market for a long term, this study provides evidence on the performance of some fundamental indicators that can help predict long run stock performance. The findings suggest that investors can distinguish between high-performing and low-performing stocks based on stock quality indicators.Originality/valueThis is the first such study to look into the performance of quality investing in the Indian stock market. As most quality investing studies have been focussed on developed economies, this paper provides out-of-sample evidence for quality investing in the context of an emerging market.

Voluntary disclosure and quality of new stock companies’ earnings forecast in EU-regulated markets

International Business and Global Economy » 2018 » Tom 37 » Voluntary disclosure and quality of new stock companies’ earnings forecast in EU-regulated markets A A A

QFII Shareholding, the Performance of Listed Companies and the Quality of Stock Market: An Empirical Test on the Data of China from 2009 to 2017

By selecting the shares on Shanghai Stock Exchange of China held by QFII from 2009 to 2017 as the research sample and by using Stata12, Excel software, this paper studies the effect on the quality of the stock market caused by QFII holdings, scale of listed companies, their performance, and etc. through descriptive statistics, regression, and dummy variable regression methods. Empirical studies have found that QFII investment behavior is more rational and the ability of stock selection is stronger. Most of the stocks they hold have excellent performance and large market values; QFII holdings enhanced liquidity of the stock and reduced the volatility of stock prices, which tends to stabilize the stock price; QFII stock ownership has the biggest impact on the market quality of large and medium-sized stocks, but has a weak impact on small-cap stocks. The listed company who has better performance and larger current market value can achieve better stock liquidity and stability. China should continue to expand the QFII team, encouraging it to participate in the corporate governance activities of listed companies and tap the potential small-cap growth stocks, and allows excellent QFII to issue funds or other financial products at home and abroad. Chinese listed companies should actively improve their performance, strengthen cooperation with QFII to optimize corporate governance and strengthen market value management.

Consideration of quality change of railway transport maintenance operations in managing costs of goods transport

the authors reviewed the quality of operational work of railway transport in the cost management system, presented methods for assessing the impact of the quality of rolling stock on the current costs of transportation activities, considered the issues of the impact of the quality of operational work on the formation of freight market demand and of financial result of the transport company - the owner of infrastructure and traction rolling stock, represented methods of assessing financial and economic efficiency of improving the quality of operational work for the company - a participant of the freight market.

The Cross-Sectional Spillovers of Single Stock Circuit Breakers

This paper uses transaction data to estimate how single stock circuit breakers on the London Stock Exchange affect other stocks that remain in continuous trading. This ‘spillover’ effect is estimated by calculating the effect of a trading halt on the market quality of stocks that remain in continuous trading and comparing this with the effect of a stock whose absolute returns are of a magnitude nearly sufficient to trigger a trading halt but do not do so. Market quality is measured using a combination of trading costs, volatility and volume. We find that circuit breakers lead to a significant improvement in the liquidity, and reduction in the volatility, of stocks that remain in continuous trading. This might suggest that — at least over the period covered by our data — single stock circuit breakers play an important role in reducing the spillover of poor market quality across stocks.

RECONSTRUCTION OF INFRASTRUCTURE LLC "AVTOMIR"

The need for the reconstruction of existing auto service enterprises is caused by changes in the structure of the rolling stock, the design of cars and the conditions of their operation, increasing the requirements for the quality of rolling stock, the design of cars and their operating conditions, increasing the quality requirements for maintenance and repair, saving fuel and energy resources and quality assurance of the environment. In our case, the need to reconstruct the autoservice company LLC "Avtomir" is associated with the need to switch to maintenance and storage of new types of rolling stock, as well as changes in the dynamics of demand for cars. In LLC Avtomir there is no possibility of rendering services related to damage to the body of the car, which reduces the ability of the organization to receive additional income, as this type of damage owners of vehicles have to eliminate at other service stations. This fact puts the company in front of the need to create a paint and body shop in the future. The purpose of this work was the development of measures to reconstruct the infrasructure of LLC "Avtomir". The main results of the technological calculation of the enterprise are as follows: - the annual workload of the technical service station is 43529 man-hour; - annual scope of works of washing, maintenance, lubrication, adjusting for setting the angles of the front wheels, adjusting brakes, maintenance and repair of the power system, electrical, tire fitting 4913; 15235.2; 2176.5; 2611.7; 3917.6; 4353; 4353; 2285 and 914 man-hour respectively; - the annual volume of works at the tire fitting site, on the maintenance and repair site of the power supply system, electrical, maintenance units is 2133; 762; 4788.2 man-hour respectively; - necessary number of production workers for maintenance and technical maintenance 29 (technological) and 35 (staff), as well as the number of auxiliary 4 and engineering - technical 5 workers; - the necessary number of posts for washing, maintenance, lubricants, technical maintenance, adjusting for setting the angles of the front wheels, adjusting for the brakes, maintenance and repair of the power system, electrical 4; 1; 1; 1; 1; 1 and 1 respectively. Analysis of production and economic activities of the enterprise allowed us to identify the objectives of the enterprise, the dynamics of its development, the state of the production and technical base. This makes it possible to identify the main shortcomings in the functioning of the organization and to implement the formulation of new tasks that need to be solved in the future. Namely, LLC "Avtomir" needs to increase production capacity, namely the addition of a diagnostic post and one more car acceptance post. In addition, there is a need to implement the washing zone, and on the vacated area to arrange a painting and drying chamber and a preparation site for painting works.

Back to basics: Is it time for a housing-first approach to community regeneration?

Why did voters in West Wales and the Valleys vote for Brexit despite £4bn of European Structural Funding being pumped into the region to regenerate the economy, housing and communities? Many must have walked past the brand new bypasses on their way to the polling station. They now act as metaphor — with a perception that the regeneration has quite simply passed them by. Despite the housing sector’s best efforts to improve the quality of ageing housing stock and regenerating communities, poverty remains well-entrenched. Regeneration, as a discipline, needs to reflect on this and we need to think differently about our approach.