Effects of Wolbachia Infection, Parasitic Order, And Time Interval On The Outcome of Inter-Strain Intrinsic Competition Between Bisexual Strain And Wolbachia-Induced Thelytokous Strain of Egg Parasitoid, Trichogramma Dendrolimi

Parasitoids may deposit a second clutch of eggs on a host that has been parasitized by the same parasitoid species. This is termed “superparasitism”. Wolbachia infection increases the superparasitism frequency of Trichogramma females. We investigated the outcome and fitness cost of inter-strain intrinsic competition between Wolbachia-infected thelytokous strain (TDW) and uninfected bisexual strain (TDB) of Trichogramma dendrolimi. To determine the developmental rate of both strains, the size of immature stages of T. dendrolimi offspring at different times after parasitization was measured in single parasitism and superparasitism conditions. The results showed increased superparasitism by Wolbachia-infected females compared to uninfected females, regardless of the time interval between oviposition; Trichogramma females were unable to distinguish between host eggs previously parasitized by TDB or TDW females. When the first oviposition was performed by TDB females, the TDB offspring outcompeted TDW offspring deposited later. However, although the TDW offspring was deposited 8 h earlier than the TDB offspring, it gained no advantage over TDB offspring. Regardless of parasitism conditions, the differences in development rate and time between TDW and TDB offspring were not significant. This study revealed that albeit TDW females presented a higher tendency of superparasitism than TDB females, TDB offspring outcompeted TDW offspring even when the latter was deposited 8 h earlier. The negative effects of Wolbachia infection on the competitive ability of TDW offspring inside the host eggs were due to offspring’s low fitness rather than delayed development.

The Impact of Trade Deficit in Nepalese Economy

The objective of this paper is to study and analyze the growth and direction of Nepalese foreign trade along with the causes and recommendations of trade deficit. Efforts have been made to sort out the principal sources of the trade deficit in Nepal. Landlockedness, political instability, lack of export diversification, devaluation of domestic currency, lack of resources, etc. are the major causes of the trade deficit in Nepal. Nepal, being not self-reliant on factors of production, consumer goods and capital goods, needs to import goods from abroad. On another hand, Nepal’s exports are heavily concentrated; both in terms of product and destination. Nepal’s major trading partners are India, China, U.A.E, etc. During the year 2019/20, Nepal exports goods worth RS. 97.71 Billion And import goods worth RS. 1196.80 billion Leading to a trade deficit of Rs.1099.09 Billion. Trade deficit is acting as negative catalyst in the economic growth and GDP of a country. Increased deficit has caused suppressed inflation. Import to export ratio is continuously increasing as demand is increasing and these demands could not be met by the domestic producers. During the year 2019/20, the contribution of trade on GDP of Nepal is 40.65%. No doubt, trade is an engine of economic growth. So, after analyzing barriers in the foreign trade, some of the steps to be taken are recommended which includes the development of competitive ability and enhancement of Human Resources, commodity and market diversification, formulation of strong legal framework and trade policy, incentives for the promotion of export and priority in the agricultural and hydropower sectors.

Competitive ability of canola (Brassica napus var. oleifera) hybrids with black oat (Avena strigosa) in a subtropical environment

The objective of this study was to assess the competitive ability of canola (Brassicanapus var. oleifera) hybrids in competition with black oat (Avena strigosa) in a subtropical environment. The experiments were conducted in a greenhouse where canola hybrids ‘Hyola 61,’ ‘Hyola 76,’ ‘Hyola 433,’ and ‘Hyola 571’ were tested individually for their competitive performance with black oat. The plant proportion between black oat and the canola hybrid was changed (100%:0%; 75%:25%; 50%:50%; 25%:75%; and 0%:100%) while keeping the total population of plants constant (20 plants plot‑1). Photosynthesis rate (μmol m-2 s-1), internal CO2 concentration (μmol mol-1), and transpiration rate (mol H2O m-2 s-1) were assessed using an infrared gas analyzer 55 days after emergence. Leaf area (m2 m-2) and dry matter (g m-2) were also assessed on the same day. The data set was analyzed by the replacement series method for competition studies. There was evidence of intense competition between canola and black oat, independent of plant proportion. The competitive ability of canola was distinct among hybrids; Hyola 571 performed better than the others in the competition against black oat. Choosing the most competitive hybrid, such as Hyola 571, helps maintain high canola grain yield levels in areas infested with black oat. Highlights: There is difference in competition among canola hybrids against black oat; Hyola 571 performed better in the competition; Preference should be given for most competitive canola genotypes against weeds, and weed control should be carried out early in the critical period of interference; Aggressiveness is the most preponderant parameter in determining canola genotypes with superior ability in competition against weeds.

Quantifying the Invasive Secondary Metabolome

Invasive plants drive ecosystem degradation through developing aggressive phenotypes that can outcompete native flora. Several hypotheses explain this, like the Evolution of Increased Competitive Ability hypothesis and the Novel Weapons Hypothesis, but none have been proven conclusively. Changes in plant metabolites are critical to these hypotheses, but complete invasive secondary metabolomes have not been quantified. Here, statistical and unsupervised machine-learning approaches were used to analyse chemotype-to-phenotype relationships in invasive and non-invasive populations in species Ageratum conyzoides, Lantana camara, Melaleuca quinquenervia and Psidium cattleainum and on a family level analysing Asteraceae, Myrtaceae and Verbenaceae. Invasive metabolomes evolved according to the EICA and NWH, involving optimisation of aggressive strategies present in native populations and local adaptation.Abstract Figure

Land Equivalent Ratio of Cowpea–Sorghum Relay Intercrop as Affected by Different Cattle Manure Application Rates Under Smallholder Farming System

Poor soil fertility is a major challenge to crop production in the communal farming areas of Zimbabwe. Intercropping legumes and cereals is a common soil fertility management technology among the farmers. A 3-year field experiment was conducted to evaluate cowpea–sorghum relay intercropping advantages in response to different cattle manure application rates. A 3 × 4 factorial experiment laid in a completely randomized block design (CRBD) with three replicates was conducted. The treatments were three cropping systems (sorghum sole, cowpea sole, and cowpea–sorghum intercrop) and four cattle manure application rates (0, 50, 75, and 100%). Crop growth rate (CGR), grain yield, harvest index (HI), relative competitive ability of each crop, and land equivalent ratio (LER) were measured. Analysis of variance and non-linear regression analyses were done to determine the yield benefits of cowpea–sorghum intercrop and estimate the relative competitive ability, respectively. Application of >75% cattle manure in a cowpea–sorghum intercrop enhanced the sorghum grain yield (75%) and HI (125%) of unmanured cowpea–sorghum plots. Cowpeas had higher CGR (159.6, 166.7 and 149.5 g m−2 day−1 at 7, 21, and 35 days after planting, respectively) at >75% cattle manure application rates on both intercrop and sole cropping than sorghum but with lower grain yield (1.4 t ha−1). Intraspecific competitive stress in sorghum was reduced at a high (>75%) quantity of manure applied. The effects of the intraspecific competition in cowpea were stronger (0.693) on grain yield than biomass at >75% manure application rates. The LER was >1 in all the treatments and was highest (2.73) under the cowpea–sorghum relay intercrop without cattle manure. Cattle manure application at 75% in a cowpea–sorghum intercrop enhanced the grain yield in sorghum and vegetative growth in cowpeas. It is therefore recommended to use the >75% cattle manure application rate in the intercrop if one wants higher grain in sorghum and high biomass in cowpeas possibly for fodder. Further studies are recommended to quantify the rate of increase in available N under the cowpea–sorghum relay intercrop with >75% cattle manure application rates.

Algorithm for forming the cluster of labor instruments of investments-perspective production systems in shipbuilding

Статья посвящена проблеме повышения эффективности управления реструктуризацией производственных систем (ПС) судостроения в целях поддержания конкурентоспособности предприятий и повышения привлекательности судостроения для инвесторов. Авторами, с использованием метода направленного поиска рационального варианта и кластерной группировки элементов ПС, предложен алгоритм и математическая модель определения экономически перспективных точек ПС судостроения, нуждающихся в инновационных преобразованиях. Научная методология исследования основана на фундаментальных положениях теории графов и комплексном рассмотрении вопросов управления изменениями в хозяйственных системах. Реализация предложенного алгоритма может быть использована для «количественного» решения управленческих задач эффективного развития ПС судостроительного предприятия и повышения его рыночной стоимости. Это создаст предпосылки к эффективному воспроизводству капитала в реальном производстве и хеджированию финансовых рисков, сопутствующих этим процессам в судостроении. This article considers issue of increasing efficiency of restructuring management of production systems (PS) in shipbuilding in order to support competitive ability of yards and to increase appeal of shipbuilding industry for investors. Authors by using method of directed search of rational option and cluster grouping of PS components propose an algorithm and mathematical model for determination of economically perspective components of PS in shipbuilding that need innovative conversion. Scientific methodology of present research is based on fundamental provisions of graph theory and integrated consideration of issues, related to change management in business systems. Implementation of proposed algorithm may be used for quantitative solution of management problems, related to effective development of PS of yard and for increasing market value of the same. This will create background for effective reproduction of capital in real production and hedging of financial risks, related to this process in shipbuilding.

Modelling Customer Satisfaction with Food

Purpose: The subject of the article is the relationship between customer satisfaction, loyalty and personality characteristics. It aims to analyse factors that influence customer satisfaction and loyalty, including their mutual relationships. For this purpose, a comprehensive model of customer satisfaction was created. Methodology/Approach: The research was carried out using a questionnaire survey on a sample of 1,530 customers of food producers (and 103 food business products that were non-durable) corresponding to the Czech population in terms of gender, age and region. The questionnaires were statistically evaluated using Structural equation modelling (SEM). Findings: The results show that a strong link between standard customer satisfaction factors (perceived quality, perceived value, customer expectation) overshadows the influence of weaker factors (personality). However, this effect is fully demonstrated when these strong factors are filtered out. Research Limitation/Implication: The paper focuses on foods that are sold through retail intermediaries, which also affect customer satisfaction. It may be different for other types of products and services and for products sold otherwise. It can also be limited to CR, resp. transition economics, ie. that in developed countries it could be different. Originality/Value of paper: The contribution of the paper is the finding that customer satisfaction is influenced by a personality factors, whose effect is at first glance weaker. It also shows that the factor image can be constructed taking into account the competitive ability of the company as a hybrid and the functionality of the customer loyalty factor influences the way of its construction.

Acoustic and postural displays in a miniature and transparent teleost fish, Danionella dracula

Individuals can reveal their relative competitive ability or mate quality through acoustic communication, varying signals in form and frequency to mediate adaptive interactions including competitive aggression. We report robust acoustic displays during aggressive interactions for a laboratory colony of Danionella dracula, a recently discovered miniature and transparent species of teleost fish closely related to zebrafish (Danio rerio). Males produce bursts of pulsatile, click-like sounds and a distinct postural display, extension of a hypertrophied lower jaw, during resident-intruder dyad interactions. Females lack a hypertrophied lower jaw and show no evidence of sound production or jaw extension under such conditions. Novel pairs of size-matched or mismatched males were combined in resident-intruder assays where sound production and jaw extension could be linked to individuals. Resident males produce significantly more sound pulses than intruders in both dyad contexts; larger males are consistently more sonic in size-mismatched pairs. For both conditions, males show a similar pattern of increased jaw extension that frequently coincided with acoustic displays during periods of heightened sonic activity. These studies firmly establish D. dracula as a sound-producing species that modulates both acoustic and postural displays during social interactions based on either residency or body size, thus providing a foundation for investigating the role of these displays in a new model clade for neurogenomic studies of aggression, courtship and other social interactions.